Swap two bits of integer at given position in scala

Scala program for Swap two specific bits of a integer. Here problem description and other solutions.

/*
  Scala program for
  Swap two bits in an integer
*/
class BitExchange()
{
	// Swap two bits in a given decimal number and position
	def swapBits(n: Int, a: Int, b: Int): Unit = {
		if (a < 0 || b < 0)
		{
			print("\n Invalid bit position (" + a + "," + b + ")");
			return;
		}
		// Get first bit
		var b1: Int = 1 & (n >> a);
		// Get Second bit
		var b2: Int = 1 & (n >> b);
		var result: Int = n;
		if (b1 != b2)
		{
			// When b1 and b2 not same
			// Swap bits
			result = n ^ ((1 << a) | (1 << b));
		}
		// Display calculated result
		println("\n Number : " + n + "");
		println(" Swap bits : (" + a + "," + b + ")");
		println(" Output : " + result);
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var task: BitExchange = new BitExchange();
		// Test cases
		// ---------------------
		// num = 16 Binary(10000)
		// (16) Change bit (1,4) 
		// 10000 => 00010 (2)
		// ↑  ↑
		task.swapBits(16, 1, 4);
		// num = 35 Binary(00100011)
		// (35) Change bit (6,0)
		// 00100011 (35) =>  01100010 (98)
		//  ↑     ↑
		task.swapBits(35, 6, 0);
		//  00001111 (15)  => 11110000 (1s) => (11110001) (2s)
		//  11110001 (-15) => Change bit (5,1)
		//  11110001 (-15) => 11010011 (-45)
		//    ↑   ↑
		task.swapBits(-15, 5, 1);
		// 1010 (10) Change bit (1,3)
		// ↑ ↑
		// Bit value of 1 and 3 are similar
		task.swapBits(10, 1, 3);
	}
}

Output

 Number : 16
 Swap bits : (1,4)
 Output : 2

 Number : 35
 Swap bits : (6,0)
 Output : 98

 Number : -15
 Swap bits : (5,1)
 Output : -45

 Number : 10
 Swap bits : (1,3)
 Output : 10