谁能解释一下这段基于 IIFE（立即调用的函数表达式）概念的代码的输出

Question

(function(value){

    var names = ["January","February","March","April","May","June","July",
                  "August","September","October","November","December"];

    value.name = function(number){
            return names[number];
    };

    value.number = function(name){
            return names.indexOf(name);
    };
})(this.month = {});

console.log(month.name(2));
console.log(month.number("November"));

请帮我解释一下这个程序是如何工作的。我不明白为什么要在函数外创建一个新对象以及为什么使用 this 运算符。

Answer 1

this 将是全局对象（因为它没有在函数内部使用）。

this.month = {} 将新对象分配给全局对象上的 month。

赋值作为分配的值计算，以便传递给函数。

从本质上讲，这只是一种丑陋且不直观的书写方式：

function myFunction(value) {

    var names = ["January", "February", "March", "April", "May", "June", "July",
        "August", "September", "October", "November", "December"
    ];

    value.name = function(number) {
        return names[number];
    };

    value.number = function(name) {
        return names.indexOf(name);
    };
}

var month = {};
myFunction(month);
console.log(month.name(2));
console.log(month.number("November"));

它使用 this 因为你不能在用于调用函数的 () 中使用 var。

谁能解释一下这段基于 IIFE（立即调用的函数表达式）概念的代码的输出

Can anyone explain the output for this code which is based on the concept of IIFE (Immediately Invoked Function Expression)

javascript

iife