ALL the test cases failed

import java.util.*;
public class Main {
public static void main(String args[]) {
float a,b,result;
char ch;
Scanner scn=new Scanner(System.in);
do {
System.out.print(“Enter the operation you wanna perform:”);
ch=scn.next().charAt(0);
switch(ch) {
case (’+’):
System.out.print(“Addition”);
a=scn.nextFloat();
b=scn.nextFloat();
result=a+b;
System.out.print(result);
break;

		case ('-'):
			System.out.print("Subtraction");
		    a=scn.nextFloat();
		    b=scn.nextFloat();
		    result=a-b;
		    System.out.print(result);
		    break;
		    
		case ('*'):
			System.out.print("Multiplication");
		    a=scn.nextFloat();
		    b=scn.nextFloat();
		    result=a*b;
		    System.out.print(result);
		    break;
		    
		case ('/'):
			System.out.print("Division");
		    a=scn.nextFloat();
		    b=scn.nextFloat();
		    result=a/b;
		    System.out.print(result);
		    break;
		    
		case ('X'):
			System.exit(0);
		 break;

		case ('x'):
			System.exit(0);
		 break; 
		    
		
			}
	}
	while(ch!='X' && ch!= 'x');
	
}

}

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