# Find first digit of a number

Here given code implementation process.

``````// C Program
// Find first digit of a number
// In constant time
#include <stdio.h>
#include <math.h>

int absValue(int num)
{
if(num < 0)
{
return -num;
}
return num;
}

void firstDigit(int num)
{
// Get absolute value
int v = absValue(num);

// Get number of digit - 1
int digits = (int)log10(v);

// Find first digit
int result = (int)(v / pow(10, digits));

// Display given number
printf("\n Given Number : %d",num);

// Display first digit
printf("\n First Digit  : %d\n",result);
}

int main()
{
// Test
firstDigit(7452);
firstDigit(1633);
firstDigit(-81633);
firstDigit(348952);
return 0;
}``````

#### Output

`````` Given Number : 7452
First Digit  : 7

Given Number : 1633
First Digit  : 1

Given Number : -81633
First Digit  : 8

Given Number : 348952
First Digit  : 3``````
``````// Java program for
// Find first digit of a number
public class Digits
{
public int absValue(int num)
{
if (num < 0)
{
return -num;
}
return num;
}
public void firstDigit(int num)
{
// Get absolute value
int v = absValue(num);
// Get number of digit - 1
int digits = (int) Math.log10(v);
// Find first digit
int result = (int)(v / Math.pow(10, digits));
// Display given number
System.out.println("\n Given Number : " + num);
// Display first digit
System.out.println(" First Digit : " + result);
}
public static void main(String[] args)
{
// Test
}
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````// Include header file
#include <iostream>
#include <math.h>
using namespace std;
// C++ program for
// Find first digit of a number
class Digits
{
public: int absValue(int num)
{
if (num < 0)
{
return -num;
}
return num;
}
void firstDigit(int num)
{
// Get absolute value
int v = this->absValue(num);
// Get number of digit - 1
int digits = (int) log10(v);
// Find first digit
int result = (int)(v / pow(10, digits));
// Display given number
cout << "\n Given Number : " << num << endl;
// Display first digit
cout << " First Digit : " << result << endl;
}
};
int main()
{
// Test
return 0;
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````package main
import "math"
import "fmt"
// Go program for
// Find first digit of a number
type Digits struct {}
func getDigits() * Digits {
var me *Digits = &Digits {}
return me
}
func(this Digits) absValue(num int) int {
if num < 0 {
return -num
}
return num
}
func(this Digits) firstDigit(num int) {
// Get absolute value
var v int = this.absValue(num)
// Get number of digit - 1
var digits int = int(math.Log10(float64(v)))
// Find first digit
var result int = int((float64(v) / math.Pow(10, float64(digits))))
// Display given number
fmt.Println("\n Given Number : ", num)
// Display first digit
fmt.Println(" First Digit : ", result)
}
func main() {
var task * Digits = getDigits()
// Test
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````// Include namespace system
using System;
// Csharp program for
// Find first digit of a number
public class Digits
{
public int absValue(int num)
{
if (num < 0)
{
return -num;
}
return num;
}
public void firstDigit(int num)
{
// Get absolute value
int v = this.absValue(num);
// Get number of digit - 1
int digits = (int) Math.Log10(v);
// Find first digit
int result = (int)(v / Math.Pow(10, digits));
// Display given number
Console.WriteLine("\n Given Number : " + num);
// Display first digit
Console.WriteLine(" First Digit : " + result);
}
public static void Main(String[] args)
{
// Test
}
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````<?php
// Php program for
// Find first digit of a number
class Digits
{
public	function absValue(\$num)
{
if (\$num < 0)
{
return -\$num;
}
return \$num;
}
public	function firstDigit(\$num)
{
// Get absolute value
\$v = \$this->absValue(\$num);
// Get number of digit - 1
\$digits = (int) log10(\$v);
// Find first digit
\$result = (int)(\$v / pow(10, \$digits));
// Display given number
echo("\n Given Number : ".\$num.
"\n");
// Display first digit
echo(" First Digit : ".\$result.
"\n");
}
}

function main()
{
// Test
}
main();``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````// Node JS program for
// Find first digit of a number
class Digits
{
absValue(num)
{
if (num < 0)
{
return -num;
}
return num;
}
firstDigit(num)
{
// Get absolute value
var v = this.absValue(num);
// Get number of digit - 1
var digits = parseInt(Math.log10(v));
// Find first digit
var result = parseInt((v / Math.pow(10, digits)));
// Display given number
console.log("\n Given Number : " + num);
// Display first digit
console.log(" First Digit : " + result);
}
}

function main()
{
// Test
}
main();``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````import math
#  Python 3 program for
#  Find first digit of a number
class Digits :
def absValue(self, num) :
if (num < 0) :
return -num

return num

def firstDigit(self, num) :
#  Get absolute value
v = self.absValue(num)
#  Get number of digit - 1
digits = int(math.log10(v))
#  Find first digit
result = int((v / 10 ** digits))
#  Display given number
print("\n Given Number : ", num)
#  Display first digit
print(" First Digit : ", result)

def main() :
#  Test

if __name__ == "__main__": main()``````

#### Output

`````` Given Number :  7452
First Digit :  7

Given Number :  1633
First Digit :  1

Given Number :  -81633
First Digit :  8

Given Number :  348952
First Digit :  3``````
``````#  Ruby program for
#  Find first digit of a number
class Digits
def absValue(num)
if (num < 0)
return -num
end

return num
end

def firstDigit(num)
#  Get absolute value
v = self.absValue(num)
#  Get number of digit - 1
digits = Math.log10(v).to_i
#  Find first digit
result = (v / 10 ** digits).to_i
#  Display given number
print("\n Given Number : ", num, "\n")
#  Display first digit
print(" First Digit : ", result, "\n")
end

end

def main()
#  Test
end

main()``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3
``````
``````// Scala program for
// Find first digit of a number
class Digits()
{
def absValue(num: Int): Int = {
if (num < 0)
{
return -num;
}
return num;
}
def firstDigit(num: Int): Unit = {
// Get absolute value
var v: Int = absValue(num);
// Get number of digit - 1
var digits: Int = Math.log10(v).toInt;
// Find first digit
var result: Int = (v / Math.pow(10, digits.toDouble)).toInt;
// Display given number
println("\n Given Number : " + num);
// Display first digit
println(" First Digit : " + result);
}
}
object Main
{
def main(args: Array[String]): Unit = {
var task: Digits = new Digits();
// Test
}
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````
``````import Foundation;
// Swift 4 program for
// Find first digit of a number
class Digits
{
func absValue(_ num: Int) -> Int
{
if (num < 0)
{
return -num;
}
return num;
}
func firstDigit(_ num: Int)
{
// Get absolute value
let v: Int = self.absValue(num);
// Get number of digit - 1
let digits: Int = Int(log10(Float(v)));
// Find first digit
let result: Int = Int((Float(v) / pow(10, Float(digits))));
// Display given number
print("\n Given Number : ", num);
// Display first digit
print(" First Digit : ", result);
}
}
func main()
{
// Test
}
main();``````

#### Output

`````` Given Number :  7452
First Digit :  7

Given Number :  1633
First Digit :  1

Given Number :  -81633
First Digit :  8

Given Number :  348952
First Digit :  3``````
``````// Kotlin program for
// Find first digit of a number
class Digits
{
fun absValue(num: Int): Int
{
if (num < 0)
{
return -num;
}
return num;
}
fun firstDigit(num: Int): Unit
{
// Get absolute value
val v: Int = this.absValue(num);
// Get number of digit - 1
val digits: Int = Math.log10(v.toDouble()).toInt();
// Find first digit
val result: Int = (v / Math.pow(10.0, digits.toDouble())).toInt();
// Display given number
println("\n Given Number : " + num);
// Display first digit
println(" First Digit : " + result);
}
}
fun main(args: Array < String > ): Unit
{
// Test
}``````

#### Output

`````` Given Number : 7452
First Digit : 7

Given Number : 1633
First Digit : 1

Given Number : -81633
First Digit : 8

Given Number : 348952
First Digit : 3``````

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