获取数组键名

Question

我有一个 JSON 这样的：

{
        "myName":{
                 "forename":"alf",
                 "surname":"cool",
                 "phone":"000000000000",
                 "email":"mail@com"
},.....

我可以访问每个键的代码

 for (var key in contacts) {
                          if (contacts.hasOwnProperty(key)) {
                                var newRow = new Element('li');
                                newRow.addClass('contact');
                                newRow.set('html', contacts[key].forename + ' ' + contacts[key].surname);

                                var innerSpan = new Element('span').set('html', contacts[key].phone + ', ' + contacts[key].email);
                                innerSpan.addClass('details');
                                innerSpan.set('html', contacts[key].phone + ', ' + contacts[key].email);
                                innerSpan.inject(newRow);

                                newRow.addEvent("click", this.setFromContact.bind(this, contacts[key]));
                                newRow.inject($(this.list));
                               // save myName to a variale here!!

                          }
                 }

现在我想 "myName" 保存到一个变量。

Answer 1

您可以测试键的值，如果值为 "myName" 您可以将其保存到变量中。

var myName = '';
for (var key in contacts) {
    if(key == "myName")
        myName = key;
}

Answer 2

// Variable with the "myName" object    
var myVariable = contacts[key];

key变量为字符串，如"myName"

Answer 3

此外，MooTools 和 ES5 提供 Object.keys

var obj = {
    myName: { }
    yourName: { }
};

console.log(Object.keys(obj)); // ['myName', 'yourName'];

我还建议您使用 Object.each(obj, fn(value, key, obj){}) 作为迭代器。参见 http://mootools.net/core/docs/1.5.1/Types/Object#Object:Object-each

它给你一个闭包，这样变量就不会重新声明并且不会相互干扰。

var keys = [];
Object.each(contacts, function(value, key){
    var newRow = new Element('li.contact').set('html', '{forename} {surname}'.substitute(value)),
        innerSpan = new Element('span.details').set('html', '{phone}, {email}'.substitute(value)).inject(newRow);

    newRow.addEvent("click", this.setFromContact.bind(this, value)).inject($(this.list));
    keys.push(key); // avoids extra Object.keys call
}, this);

获取数组键名

get name of array key

javascript

mootools