Golang：在函数中使用一个值返回多个参数

Question

Suppose in Go we have a function returning two arguments

func squareAndCube(int side) (square int, cube int) {
    square = side * side
    cube = square * side
    return
}

Then you would like to use the first (second) value of this function in the conditional:

square, _ := squareAndCube(n)
if square > m {
    ...
}

However, can we do first two lines in one line if we do not need the value square to use anywhere else? E.g.

 if squareAndCube(n).First() > m {
     ...
 }

Answer 1

You cannot pick one of the multiple returned values but you can write something like

if square, _ := squareAndCube(n); square > m {
    // ...
}

The square variable will only be valid in the if scope. These "simple statements" can be used in if statements, switch statements and other constructs such as for loops.

See also the effective go article on if statements.