Swap 2 variables' value

Question

//Please explain why this statement doesn't work in Java:
//a -= b = (a += b) -b;
//Thanks

public static void main(String[] args) {
int a = 5, b = 7;
System.out.printf("a = %d, b = %d\n",a,b);
//Swap a and b without using another variable
//Work in C and Java
a += b;
b = a - b;
a -= b;
//But when I use this statement:
// a -= b = (a += b) -b;
//Only work in C and not in Java
System.out.printf("a = %d, b = %d\n",a,b);
}

Answer 1

https://code.sololearn.com/cBy0xwZG5d6G/?ref=app

Answer 2

@Shikamaru: your statement is easer to understand and works in both C and Java. Nice.

But I also want to know the problem in the statement:
a -= b = (a += b) -b;