关闭返回如何工作？

Question

我有两个简单闭包的例子，我的问题是我什么时候应该返回带或不带括号的函数？谢谢！

示例1：

function names (first, last) {
    var intro = "My name is ";
    function full_Name () {
        return intro + first + " " + last;
    }
    return full_Name();   <----
}

full_Name("Macro","phages"); // My name is Macro phages

示例2：

function names (first) {
    var intro = "My name is ";
    function full_Name (last) {
        return intro + first + " " + last;
    }
    return full_Name;    <---- why not full_Name();
}

var white_cells = names("Macro");
white_cells("phages");  // My name is Macro phages

Answer 1

return foo(); 调用函数并返回其返回值（在您的示例中为intro + first + " " + last;）。

return foo;返回函数本身。