javascript - 如何在对象方法中选择 JavaScript 对象数组

Question

如何从 randomImage.imagePicker 方法中选择 randomImage.images 数组中的字符串？

(function() {

var randomImage = {

        images : [
                'http://placehold.it/100x100',
                'http://placehold.it/200x200',
                'http://placehold.it/300x300',
                'http://placehold.it/400x400'
                ],//images Array
        imagePicker : function () {
                return console.log(randomImage.images[2]);
                }()//imagePicker Method

}//randomImage Object

})()

我在控制台中收到以下错误:

Uncaught TypeError: Cannot read property 'images' of undefined

Answer 1

I get the following error in the console: Uncaught TypeError: Cannot read property 'images' of undefined

问题是在函数定义之后有 () :

imagePicker : function () {
    return console.log(randomImage.images[2]);
}()//imagePicker Method
 ^^

这将立即调用该函数并将其返回值分配给imagePicker。但此时randomImage还没有初始化。它的值仍然是未定义，这就是您收到该错误的原因。

删除括号以分配函数本身(我认为这就是您想要做的):

imagePicker : function () {
    return console.log(randomImage.images[2]);
}