javascript - 获取数组键的名称

Question

我有一个像这样的 JSON:

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

我可以访问每个 key 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!!

                          }
                 }

现在我想将“myName”保存到变量中。

Answer 1

此外，MooTools 和 ES5 提供了 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。请参阅http://mootools.net/core/docs/1.5.1/Types/Object#Object:Object-each

它为您提供了一个闭包，因此变量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);