Check if a given string is a valid number
Here given code implementation process.
/*
Java Program for
Check if a given string is a valid number
*/
public class Numerical
{
public boolean isValidNumber(String num)
{
int n = num.length();
int i = 0;
int j = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num.charAt(i) == ' ')
{
i++;
}
// Trim the white space from ending position.
while (j >= 0 && num.charAt(j) == ' ')
{
j--;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num.charAt(i) >= '0' &&
num.charAt(i) <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num.charAt(i) == '+' ||
num.charAt(i) == '-' ||
num.charAt(i) == '.' ||
num.charAt(i) >= '0' && num.charAt(i) <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num.charAt(i) == '-' || num.charAt(i) == '+')
{
// + and - at beginning
i++;
}
if (i <= j && num.charAt(i) == '-' ||
num.charAt(i) == '+')
{
if (num.charAt(i) == num.charAt(i - 1))
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i++;
}
boolean flagDot = false;
boolean flagE = false;
// Check intermediate of i to j
while (i < j)
{
if (num.charAt(i) >= '0' && num.charAt(i) <= '9')
{
// When position of i contain valid numeric digit
i++;
}
else
{
if (num.charAt(i) == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num.charAt(i - 1) == ' ') ||
(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num.charAt(i) == 'e')
{
if (flagE == true ||
i + 1 >= n ||
!(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num.charAt(i + 1) == '-' ||
num.charAt(i + 1) == '+'))
{
i++;
}
flagE = true;
}
else
{
return false;
}
i++;
}
}
return true;
}
return false;
}
public void isNumber(String num)
{
if (isValidNumber(num))
{
System.out.println(" Given (" + num + ") is valid number");
}
else
{
System.out.println(" Given (" + num + ") is not valid number");
}
}
public static void main(String[] args)
{
Numerical task = new Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number// Include header file
#include <iostream>
#include <string>
using namespace std;
/*
C++ Program for
Check if a given string is a valid number
*/
class Numerical
{
public: bool isValidNumber(string num)
{
int n = num.length();
int i = 0;
int j = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num[i] == ' ')
{
i++;
}
// Trim the white space from ending position.
while (j >= 0 && num[j] == ' ')
{
j--;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num[i] >= '0' && num[i] <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num[i] == '+' ||
num[i] == '-' ||
num[i] == '.' ||
num[i] >= '0' && num[i] <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num[i] == '-' || num[i] == '+')
{
// + and - at beginning
i++;
}
if (i <= j && num[i] == '-' || num[i] == '+')
{
if (num[i] == num[i - 1])
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i++;
}
bool flagDot = false;
bool flagE = false;
// Check intermediate of i to j
while (i < j)
{
if (num[i] >= '0' && num[i] <= '9')
{
// When position of i contain valid numeric digit
i++;
}
else
{
if (num[i] == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num[i - 1] == ' ') ||
(num[i - 1] >= '0' &&
num[i - 1] <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num[i] == 'e')
{
if (flagE == true ||
i + 1 >= n ||
!(num[i - 1] >= '0' &&
num[i - 1] <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num[i + 1] == '-' || num[i + 1] == '+'))
{
i++;
}
flagE = true;
}
else
{
return false;
}
i++;
}
}
return true;
}
return false;
}
void isNumber(string num)
{
if (this->isValidNumber(num))
{
cout << " Given (" << num << ") is valid number" << endl;
}
else
{
cout << " Given (" << num << ") is not valid number" << endl;
}
}
};
int main()
{
Numerical *task = new Numerical();
// 10e2
task->isNumber("10e2");
// num = --134
// Result = no
task->isNumber(" --134");
// num = -+123 = -123
// Result = yes
task->isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task->isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task->isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task->isNumber(" 2e1.02 ");
return 0;
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number// Include namespace system
using System;
/*
Csharp Program for
Check if a given string is a valid number
*/
public class Numerical
{
public Boolean isValidNumber(String num)
{
int n = num.Length;
int i = 0;
int j = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num[i] == ' ')
{
i++;
}
// Trim the white space from ending position.
while (j >= 0 && num[j] == ' ')
{
j--;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num[i] >= '0' && num[i] <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num[i] == '+' ||
num[i] == '-' ||
num[i] == '.' ||
num[i] >= '0' && num[i] <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num[i] == '-' || num[i] == '+')
{
// + and - at beginning
i++;
}
if (i <= j && num[i] == '-' || num[i] == '+')
{
if (num[i] == num[i - 1])
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i++;
}
Boolean flagDot = false;
Boolean flagE = false;
// Check intermediate of i to j
while (i < j)
{
if (num[i] >= '0' && num[i] <= '9')
{
// When position of i contain valid numeric digit
i++;
}
else
{
if (num[i] == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 &&
!((num[i - 1] == ' ') ||
(num[i - 1] >= '0' && num[i - 1] <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num[i] == 'e')
{
if (flagE == true ||
i + 1 >= n ||
!(num[i - 1] >= '0' && num[i - 1] <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num[i + 1] == '-' || num[i + 1] == '+'))
{
i++;
}
flagE = true;
}
else
{
return false;
}
i++;
}
}
return true;
}
return false;
}
public void isNumber(String num)
{
if (this.isValidNumber(num))
{
Console.WriteLine(" Given (" + num + ") is valid number");
}
else
{
Console.WriteLine(" Given (" + num + ") is not valid number");
}
}
public static void Main(String[] args)
{
Numerical task = new Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid numberpackage main
import "fmt"
/*
Go Program for
Check if a given string is a valid number
*/
func isValidNumber(num string) bool {
var n int = len(num)
var i int = 0
var j int = n - 1
if n == 0 {
// When string is empty
return false
}
// Trim the white space from beginning position.
for (i < n && num[i] == ' ') {
i++
}
// Trim the white space from ending position.
for (j >= 0 && num[j] == ' ') {
j--
}
if j < i {
// When string contain white space only
return false
}
if i == j && !(num[i] >= '0' && num[i] <= '9') {
// When string contains single character.
// And this is not a numeric value.
return false
}
if num[i] == '+' || num[i] == '-' ||
num[i] == '.' || num[i] >= '0' && num[i] <= '9' {
// When number start with + - and .
// This three are suitable for start a number.
if num[i] == '-' || num[i] == '+' {
// + and - at beginning
i++
}
if i <= j && num[i] == '-' || num[i] == '+' {
if num[i] == num[i - 1] {
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false
}
i++
}
var flagDot bool = false
var flagE bool = false
// Check intermediate of i to j
for (i < j) {
if num[i] >= '0' && num[i] <= '9' {
// When position of i contain valid numeric digit
i++
} else {
if num[i] == '.' {
if flagDot == true || flagE == true ||
(i > 0 && !((num[i - 1] == ' ') ||
(num[i - 1] >= '0' && num[i - 1] <= '9'))) {
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false
}
// When dot is valid
flagDot = true
} else if num[i] == 'e' {
if flagE == true || i + 1 >= n ||
!(num[i - 1] >= '0' && num[i - 1] <= '9') {
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false
}
if i + 1 <= j && (num[i + 1] == '-' || num[i + 1] == '+') {
i++
}
flagE = true
} else {
return false
}
i++
}
}
return true
}
return false
}
func isNumber(num string) {
if isValidNumber(num) {
fmt.Println(" Given (", num, ") is valid number")
} else {
fmt.Println(" Given (", num, ") is not valid number")
}
}
func main() {
// 10e2
isNumber("10e2")
// num = --134
// Result = no
isNumber(" --134")
// num = -+123 = -123
// Result = yes
isNumber(" -+123 ")
// num = .4 = 0.4
// Result = yes
isNumber(" .4 ")
// num = 000.4e-12 = 4e-13
// Result = yes
isNumber(" 000.4e-12 ")
// num = 2e1.02
// Result = No
isNumber(" 2e1.02 ")
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number<?php
/*
Php Program for
Check if a given string is a valid number
*/
class Numerical
{
public function isValidNumber($num)
{
$n = strlen($num);
$i = 0;
$j = $n - 1;
if ($n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while ($i < $n && $num[$i] == ' ')
{
$i++;
}
// Trim the white space from ending position.
while ($j >= 0 && $num[$j] == ' ')
{
$j--;
}
if ($j < $i)
{
// When string contain white space only
return false;
}
if ($i == $j && !($num[$i] >= '0' && $num[$i] <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if ($num[$i] == '+' || $num[$i] == '-' ||
$num[$i] == '.' || $num[$i] >= '0' && $num[$i] <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if ($num[$i] == '-' || $num[$i] == '+')
{
// + and - at beginning
$i++;
}
if ($i <= $j && $num[$i] == '-' || $num[$i] == '+')
{
if ($num[$i] == $num[$i - 1])
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
$i++;
}
$flagDot = false;
$flagE = false;
// Check intermediate of i to j
while ($i < $j)
{
if ($num[$i] >= '0' && $num[$i] <= '9')
{
// When position of i contain valid numeric digit
$i++;
}
else
{
if ($num[$i] == '.')
{
if ($flagDot == true ||
$flagE == true ||
($i > 0 &&
!(($num[$i - 1] == ' ') ||
($num[$i - 1] >= '0' &&
$num[$i - 1] <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
$flagDot = true;
}
else if ($num[$i] == 'e')
{
if ($flagE == true ||
$i + 1 >= $n ||
!($num[$i - 1] >= '0' &&
$num[$i - 1] <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if ($i + 1 <= $j &&
($num[$i + 1] == '-' ||
$num[$i + 1] == '+'))
{
$i++;
}
$flagE = true;
}
else
{
return false;
}
$i++;
}
}
return true;
}
return false;
}
public function isNumber($num)
{
if ($this->isValidNumber($num))
{
echo(" Given (".$num.") is valid number"."\n");
}
else
{
echo(" Given (".$num.") is not valid number"."\n");
}
}
}
function main()
{
$task = new Numerical();
// 10e2
$task->isNumber("10e2");
// num = --134
// Result = no
$task->isNumber(" --134");
// num = -+123 = -123
// Result = yes
$task->isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
$task->isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
$task->isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
$task->isNumber(" 2e1.02 ");
}
main();Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number/*
Node JS Program for
Check if a given string is a valid number
*/
class Numerical
{
isValidNumber(num)
{
var n = num.length;
var i = 0;
var j = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num.charAt(i) == ' ')
{
i++;
}
// Trim the white space from ending position.
while (j >= 0 && num.charAt(j) == ' ')
{
j--;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num.charAt(i) >= '0' && num.charAt(i) <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num.charAt(i) == '+' ||
num.charAt(i) == '-' ||
num.charAt(i) == '.' ||
num.charAt(i) >= '0' &&
num.charAt(i) <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num.charAt(i) == '-' || num.charAt(i) == '+')
{
// + and - at beginning
i++;
}
if (i <= j && num.charAt(i) == '-' || num.charAt(i) == '+')
{
if (num.charAt(i) == num.charAt(i - 1))
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i++;
}
var flagDot = false;
var flagE = false;
// Check intermediate of i to j
while (i < j)
{
if (num.charAt(i) >= '0' && num.charAt(i) <= '9')
{
// When position of i contain valid numeric digit
i++;
}
else
{
if (num.charAt(i) == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num.charAt(i - 1) == ' ') ||
(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num.charAt(i) == 'e')
{
if (flagE == true ||
i + 1 >= n ||
!(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num.charAt(i + 1) == '-' ||
num.charAt(i + 1) == '+'))
{
i++;
}
flagE = true;
}
else
{
return false;
}
i++;
}
}
return true;
}
return false;
}
isNumber(num)
{
if (this.isValidNumber(num))
{
console.log(" Given (" + num + ") is valid number");
}
else
{
console.log(" Given (" + num + ") is not valid number");
}
}
}
function main()
{
var task = new Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}
main();Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number# Python 3 Program for
# Check if a given string is a valid number
class Numerical :
def isValidNumber(self, num) :
n = len(num)
i = 0
j = n - 1
if (n == 0) :
# When string is empty
return False
# Trim the white space from beginning position.
while (i < n and num[i] == ' ') :
i += 1
# Trim the white space from ending position.
while (j >= 0 and num[j] == ' ') :
j -= 1
if (j < i) :
# When string contain white space only
return False
if (i == j and not(num[i] >= '0'
and num[i] <= '9')) :
# When string contains single character.
# And this is not a numeric value.
return False
if (num[i] == '+'
or num[i] == '-'
or num[i] == '.'
or num[i] >= '0'
and num[i] <= '9') :
# When number start with + - and .
# This three are suitable for start a number.
if (num[i] == '-'
or num[i] == '+') :
# + and - at beginning
i += 1
if (i <= j and num[i] == '-'
or num[i] == '+') :
if (num[i] == num[i - 1]) :
# When like this ++123 or --123
# ++ are used to increment and -- use to decrement
return False
i += 1
flagDot = False
flagE = False
# Check intermediate of i to j
while (i < j) :
if (num[i] >= '0'
and num[i] <= '9') :
# When position of i contain valid numeric digit
i += 1
else :
if (num[i] == '.') :
if (flagDot == True or
flagE == True or(i > 0 and
not((num[i - 1] == ' ') or(num[i - 1] >= '0'
and num[i - 1] <= '9')))) :
# Fail case
# ➀ When dot appears more than once.
# ➁ Exponent has no digits.
return False
# When dot is valid
flagDot = True
elif (num[i] == 'e') :
if (flagE == True or i + 1 >= n or
not(num[i - 1] >= '0'
and num[i - 1] <= '9')) :
# Fail case
# ➀ When e appears more than once.
# ➁ Exponent is last digit in number.
# ➂ Exponent has previous digit is not number.
return False
if (i + 1 <= j and(num[i + 1] == '-'
or num[i + 1] == '+')) :
i += 1
flagE = True
else :
return False
i += 1
return True
return False
def isNumber(self, num) :
if (self.isValidNumber(num)) :
print(" Given (", num ,") is valid number")
else :
print(" Given (", num ,") is not valid number")
def main() :
task = Numerical()
# 10e2
task.isNumber("10e2")
# num = --134
# Result = no
task.isNumber(" --134")
# num = -+123 = -123
# Result = yes
task.isNumber(" -+123 ")
# num = .4 = 0.4
# Result = yes
task.isNumber(" .4 ")
# num = 000.4e-12 = 4e-13
# Result = yes
task.isNumber(" 000.4e-12 ")
# num = 2e1.02
# Result = No
task.isNumber(" 2e1.02 ")
if __name__ == "__main__": main()Output
Given ( 10e2 ) is valid number
Given ( --134 ) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number# Ruby Program for
# Check if a given string is a valid number
class Numerical
def isValidNumber(num)
n = num.length
i = 0
j = n - 1
if (n == 0)
# When string is empty
return false
end
# Trim the white space from beginning position.
while (i < n && num[i] == ' ')
i += 1
end
# Trim the white space from ending position.
while (j >= 0 && num[j] == ' ')
j -= 1
end
if (j < i)
# When string contain white space only
return false
end
if (i == j && !(num[i] >= '0' && num[i] <= '9'))
# When string contains single character.
# And this is not a numeric value.
return false
end
if (num[i] == '+' ||
num[i] == '-' ||
num[i] == '.' ||
num[i] >= '0' && num[i] <= '9')
# When number start with + - and .
# This three are suitable for start a number.
if (num[i] == '-' || num[i] == '+')
# + and - at beginning
i += 1
end
if (i <= j && num[i] == '-' || num[i] == '+')
if (num[i] == num[i - 1])
# When like this ++123 or --123
# ++ are used to increment and -- use to decrement
return false
end
i += 1
end
flagDot = false
flagE = false
# Check intermediate of i to j
while (i < j)
if (num[i] >= '0' && num[i] <= '9')
# When position of i contain valid numeric digit
i += 1
else
if (num[i] == '.')
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num[i - 1] == ' ') ||
(num[i - 1] >= '0' &&
num[i - 1] <= '9'))))
# Fail case
# ➀ When dot appears more than once.
# ➁ Exponent has no digits.
return false
end
# When dot is valid
flagDot = true
elsif (num[i] == 'e')
if (flagE == true ||
i + 1 >= n ||
!(num[i - 1] >= '0' &&
num[i - 1] <= '9'))
# Fail case
# ➀ When e appears more than once.
# ➁ Exponent is last digit in number.
# ➂ Exponent has previous digit is not number.
return false
end
if (i + 1 <= j &&
(num[i + 1] == '-' ||
num[i + 1] == '+'))
i += 1
end
flagE = true
else
return false
end
i += 1
end
end
return true
end
return false
end
def isNumber(num)
if (self.isValidNumber(num))
print(" Given (", num ,") is valid number", "\n")
else
print(" Given (", num ,") is not valid number", "\n")
end
end
end
def main()
task = Numerical.new()
# 10e2
task.isNumber("10e2")
# num = --134
# Result = no
task.isNumber(" --134")
# num = -+123 = -123
# Result = yes
task.isNumber(" -+123 ")
# num = .4 = 0.4
# Result = yes
task.isNumber(" .4 ")
# num = 000.4e-12 = 4e-13
# Result = yes
task.isNumber(" 000.4e-12 ")
# num = 2e1.02
# Result = No
task.isNumber(" 2e1.02 ")
end
main()Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number
import scala.collection.mutable._;
/*
Scala Program for
Check if a given string is a valid number
*/
class Numerical()
{
def isValidNumber(num: String): Boolean = {
var n: Int = num.length();
var i: Int = 0;
var j: Int = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num.charAt(i) == ' ')
{
i += 1;
}
// Trim the white space from ending position.
while (j >= 0 && num.charAt(j) == ' ')
{
j -= 1;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num.charAt(i) >= '0' && num.charAt(i) <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num.charAt(i) == '+' ||
num.charAt(i) == '-' ||
num.charAt(i) == '.' ||
num.charAt(i) >= '0' &&
num.charAt(i) <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num.charAt(i) == '-' ||
num.charAt(i) == '+')
{
// + and - at beginning
i += 1;
}
if (i <= j && num.charAt(i) == '-' ||
num.charAt(i) == '+')
{
if (num.charAt(i) == num.charAt(i - 1))
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i += 1;
}
var flagDot: Boolean = false;
var flagE: Boolean = false;
// Check intermediate of i to j
while (i < j)
{
if (num.charAt(i) >= '0' && num.charAt(i) <= '9')
{
// When position of i contain valid numeric digit
i += 1;
}
else
{
if (num.charAt(i) == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num.charAt(i - 1) == ' ') ||
(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num.charAt(i) == 'e')
{
if (flagE == true || i + 1 >= n ||
!(num.charAt(i - 1) >= '0' &&
num.charAt(i - 1) <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num.charAt(i + 1) == '-' ||
num.charAt(i + 1) == '+'))
{
i += 1;
}
flagE = true;
}
else
{
return false;
}
i += 1;
}
}
return true;
}
return false;
}
def isNumber(num: String): Unit = {
if (isValidNumber(num))
{
println(" Given (" + num + ") is valid number");
}
else
{
println(" Given (" + num + ") is not valid number");
}
}
}
object Main
{
def main(args: Array[String]): Unit = {
var task: Numerical = new Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid numberimport Foundation;
/*
Swift 4 Program for
Check if a given string is a valid number
*/
class Numerical
{
func isValidNumber(_ text: String) -> Bool
{
let num = Array(text);
let n: Int = num.count;
var i: Int = 0;
var j: Int = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num[i] == " ")
{
i += 1;
}
// Trim the white space from ending position.
while (j >= 0 && num[j] == " ")
{
j -= 1;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num[i] >= "0" && num[i] <= "9"))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num[i] == "+" ||
num[i] == "-" ||
num[i] == "." ||
num[i] >= "0" && num[i] <= "9")
{
// When number start with + - and .
// This three are suitable for start a number.
if (num[i] == "-" || num[i] == "+")
{
// + and - at beginning
i += 1;
}
if (i <= j && num[i] == "-" || num[i] == "+")
{
if (num[i] == num[i - 1])
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i += 1;
}
var flagDot: Bool = false;
var flagE: Bool = false;
// Check intermediate of i to j
while (i < j)
{
if (num[i] >= "0" && num[i] <= "9")
{
// When position of i contain valid numeric digit
i += 1;
}
else
{
if (num[i] == ".")
{
if (flagDot == true ||
flagE == true ||
(i > 0 && !((num[i - 1] == " ") ||
(num[i - 1] >= "0" &&
num[i - 1] <= "9"))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num[i] == "e")
{
if (flagE == true ||
i + 1 >= n ||
!(num[i - 1] >= "0" &&
num[i - 1] <= "9"))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num[i + 1] == "-" ||
num[i + 1] == "+"))
{
i += 1;
}
flagE = true;
}
else
{
return false;
}
i += 1;
}
}
return true;
}
return false;
}
func isNumber(_ num: String)
{
if (self.isValidNumber(num))
{
print(" Given (", num ,") is valid number");
}
else
{
print(" Given (", num ,") is not valid number");
}
}
}
func main()
{
let task: Numerical = Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}
main();Output
Given ( 10e2 ) is valid number
Given ( --134 ) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number/*
Kotlin Program for
Check if a given string is a valid number
*/
class Numerical
{
fun isValidNumber(num: String): Boolean
{
val n: Int = num.length;
var i: Int = 0;
var j: Int = n - 1;
if (n == 0)
{
// When string is empty
return false;
}
// Trim the white space from beginning position.
while (i < n && num.get(i) == ' ')
{
i += 1;
}
// Trim the white space from ending position.
while (j >= 0 && num.get(j) == ' ')
{
j -= 1;
}
if (j < i)
{
// When string contain white space only
return false;
}
if (i == j && !(num.get(i) >= '0' && num.get(i) <= '9'))
{
// When string contains single character.
// And this is not a numeric value.
return false;
}
if (num.get(i) == '+' ||
num.get(i) == '-' ||
num.get(i) == '.' ||
num.get(i) >= '0' && num.get(i) <= '9')
{
// When number start with + - and .
// This three are suitable for start a number.
if (num.get(i) == '-' || num.get(i) == '+')
{
// + and - at beginning
i += 1;
}
if (i <= j && num.get(i) == '-' || num.get(i) == '+')
{
if (num.get(i) == num.get(i - 1))
{
// When like this ++123 or --123
// ++ are used to increment and -- use to decrement
return false;
}
i += 1;
}
var flagDot: Boolean = false;
var flagE: Boolean = false;
// Check intermediate of i to j
while (i < j)
{
if (num.get(i) >= '0' && num.get(i) <= '9')
{
// When position of i contain valid numeric digit
i += 1;
}
else
{
if (num.get(i) == '.')
{
if (flagDot == true ||
flagE == true ||
(i > 0 &&
!((num.get(i - 1) == ' ') ||
(num.get(i - 1) >= '0' &&
num.get(i - 1) <= '9'))))
{
// Fail case
// ➀ When dot appears more than once.
// ➁ Exponent has no digits.
return false;
}
// When dot is valid
flagDot = true;
}
else if (num.get(i) == 'e')
{
if (flagE == true ||
i + 1 >= n ||
!(num.get(i - 1) >= '0' &&
num.get(i - 1) <= '9'))
{
// Fail case
// ➀ When e appears more than once.
// ➁ Exponent is last digit in number.
// ➂ Exponent has previous digit is not number.
return false;
}
if (i + 1 <= j &&
(num.get(i + 1) == '-' ||
num.get(i + 1) == '+'))
{
i += 1;
}
flagE = true;
}
else
{
return false;
}
i += 1;
}
}
return true;
}
return false;
}
fun isNumber(num: String): Unit
{
if (this.isValidNumber(num))
{
println(" Given (" + num + ") is valid number");
}
else
{
println(" Given (" + num + ") is not valid number");
}
}
}
fun main(args: Array < String > ): Unit
{
val task: Numerical = Numerical();
// 10e2
task.isNumber("10e2");
// num = --134
// Result = no
task.isNumber(" --134");
// num = -+123 = -123
// Result = yes
task.isNumber(" -+123 ");
// num = .4 = 0.4
// Result = yes
task.isNumber(" .4 ");
// num = 000.4e-12 = 4e-13
// Result = yes
task.isNumber(" 000.4e-12 ");
// num = 2e1.02
// Result = No
task.isNumber(" 2e1.02 ");
}Output
Given (10e2) is valid number
Given ( --134) is not valid number
Given ( -+123 ) is valid number
Given ( .4 ) is valid number
Given ( 000.4e-12 ) is valid number
Given ( 2e1.02 ) is not valid number
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