How does this expression work in java?

Question

Java

a=a+b-(b=a);
I know that this line swaps the values ​​of the variables a and b, but how did the idea to do this even come about? Why is there a sum at all and why do we subtract the expression in brackets from it?

Answer 1

As you have already answered, here you need knowledge of the basics of arithmetic and logic. When it comes to programming, pay attention to operator precedence. For example, an expression enclosed in parentheses takes precedence, just like in mathematics.

2 * (2 + 2) = 8
2 * 2 + 2 = 6

The same rules apply to programming.