为什么这个条件在return语句中没有其他作用？

Question

I think that b should always be returned but the condition work both way. I read it is recommended not to use it after return statements in c.well now I got it return stops the function.

function min(a,b) {
  if(a<b) return a;
  return b; 
}

min(20,94);//20
min(20,4);//4

Answer 1

Because return breaks out of the function completely. return b is never hit if return a has already been hit, and return a will only fire if a is less than b .

The return statement ends function execution and specifies a value to be returned to the function caller.

— MDN's notes on return

In pseudo-code, your code snippet essentially performs the following:

1. It takes two arguments, a and b .
2. It then checks if a is less than b and if so, returns a - the function ends here.
3. If the check in part 2. fails, it makes it to this part and returns b . The function ends here.

min(20, 94)

Here 20 ( a ) is less than 94 ( b ), so part 2's check evaluates to true and 20 is returned. Nothing else happens.

min(20, 4)

Here 20 ( a ) is not less than 4 ( b ), so part 2's check evaluates to false and we move on to part 3 where 4 is returned. Nothing else happens.