javascript Object.keys 在 Internet Explorer 中不起作用

Object.keys not working in internet Explorer

提问by Peter Saxton

I have a program to return a list of keys from dictionary. The Code works correctly in Chrome, Opera and Firefox but not Internet Explorer. I have added alert comments to close down where the issue is. Below is the code causing the problem. The alerts are shown in the order

我有一个程序可以从字典中返回一个键列表。该代码可在 Chrome、Opera 和 Firefox 中正常运行，但不能在 Internet Explorer 中正常运行。我添加了警报评论以关闭问题所在。下面是导致问题的代码。警报按顺序显示

• App Initializing
• Getting JSON
• Got JSON
• Got Keys (Does not show in IE)

• 应用初始化
• 获取 JSON
• 得到 JSON
• 获得密钥（在 IE 中不显示）

I found a similar Question herebut I believe in this example that this isn't the correct question as I created the dictionary so it is a native object.

我在这里找到了一个类似的问题，但我相信在这个例子中这不是正确的问题，因为我创建了字典，所以它是一个本地对象。

I am no longer sure that Object.keys is the problem so here is a link to the full page. I JavaScript is in page to make it easier to view

我不再确定 Object.keys 是问题所在，因此这里是完整页面的链接。我 JavaScript 在页面中，以便于查看

http://www.londonlayout.co.uk/dev/live.htm

http://www.londonlayout.co.uk/dev/live.htm

 var myApp = {
    init: function () {
        var def = $.Deferred();
        alert('App Initializing');
        $.getJSON('data/data.json', function (raw) {
            alert('Getting JSON');
            myApp.data = raw;
            $.each(myApp.data, function (code, details) {
                try {
                    myApp.nameDict[details.name] = code;
                }
                catch (e) {}
            });
            alert('Got JSON');
            myApp.names = Object.keys(myApp.nameDict);
            alert('Got Keys')
            def.resolve();
        });
        return def.promise();
    },
    data: {},
    nameDict: {}
}

回答by jabclab

Object.keysis not avaiable in IE < 9. As a simple workaround you could use:

Object.keys是不是在IE <9缴费。作为一个简单的解决方法，您可以使用：

if (!Object.keys) {
  Object.keys = function(obj) {
    var keys = [];

    for (var i in obj) {
      if (obj.hasOwnProperty(i)) {
        keys.push(i);
      }
    }

    return keys;
  };
}

Here is a more comprehensive polyfill:

这是一个更全面的 polyfill：

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
if (!Object.keys) {
  Object.keys = (function () {
    'use strict';
    var hasOwnProperty = Object.prototype.hasOwnProperty,
        hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
        dontEnums = [
          'toString',
          'toLocaleString',
          'valueOf',
          'hasOwnProperty',
          'isPrototypeOf',
          'propertyIsEnumerable',
          'constructor'
        ],
        dontEnumsLength = dontEnums.length;

    return function (obj) {
      if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
        throw new TypeError('Object.keys called on non-object');
      }

      var result = [], prop, i;

      for (prop in obj) {
        if (hasOwnProperty.call(obj, prop)) {
          result.push(prop);
        }
      }

      if (hasDontEnumBug) {
        for (i = 0; i < dontEnumsLength; i++) {
          if (hasOwnProperty.call(obj, dontEnums[i])) {
            result.push(dontEnums[i]);
          }
        }
      }
      return result;
    };
  }());
}

回答by dalcam

Alternatively if you have access to lodash you can use keys. e.g.

或者，如果您可以访问 lodash，则可以使用keys。例如

_.keys(yourObj);

_.keys(yourObj);