有和没有return语句的函数之间有区别吗？ [英] Is there a difference between a function with and without a return statement?

问题描述

假设你有2个相同的函数没有返回值

Say you have 2 identical functions that do not return a value

function a() {
    // do some interesting things
}

function b() {
    // do the same interesting things
    return;
}

功能 b 是显然更冗长，但这些之间是否有任何功能差异？

Function b is obviously more verbose but is there any functional difference between these?

推荐答案

没有真正的区别;两者都将返回 undefined 。

There's no real difference; both will return undefined.

没有return语句的函数将返回 undefined ，以及带有空的函数返回声明。

Functions with no return statement will return undefined, as will functions with an empty return statement.

要自己确认，可以运行此代码 - FIDDLE ：

To confirm this for yourself, you can run this code -- FIDDLE:

​function a() {
}

function b() {
    return;
}

var aResult = a();
var bResult = b();

alert(aResult === bResult);  //alerts true

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