ES6与ES5中的set等效 [英] Equivalent of set in ES6 to ES5

问题描述

我有一个要在ES6中进行迭代的集合.我正在尝试将其转换为ES5中的等效版本.由于ES6，我的构建失败了.这就是为什么我将其转换为ES5.

I have a set over which I am iterating in ES6. I am trying to convert it to its equivalent in ES5. My build is getting failed because of ES6. That's why I am converting it to ES5.

这是我在ES6中的代码

Here's my code in ES6

service.getDevices = function (date) {
        var result = [];
        var deviceList = devices[date.getTime()];

        for (let item of deviceList) { // browser compatibility: support for ECMA6
            result.push({"deviceName": item});
        }

        return result;
    }

由于"let"，我遇到了错误.我尝试使用for (var item in deviceList)，它不显示图表.

I am getting error because of 'let'. I tried using for (var item in deviceList), it does not display the charts.

我也尝试过:

for(var i = 0; i < deviceList.length(); i++){
           result.push({"deviceName" : deviceList[i]});
       }

即使这不适用于set.有人可以帮我告诉我如何遍历ES5中的集合吗?如果那不可能，是否有任何等效的方法呢?

Even this is not working for set. can someone help and tell me how to iterate over a set in ES5 and if that is not possible, is there any equivalent way of doing it?

推荐答案

我认为第二个for示例的问题只是length是属性而不是函数，因此您不应该添加()到最后一个有效的版本可能如下所示:

I think your problem with your second for example is just that length is a property and not a function so you shouldn't add () to the end of it. A working version of this might look like this:

for(var i = 0; i < deviceList.length; i++){
  result.push({"deviceName" : deviceList[i]});
}

这假定(如 @grabantot 指出)deviceList是一个数组，但是，如果它是一个Set，那么您需要使用deviceList.size属性.

This assumes (as @grabantot pointed out) that deviceList is an array, however, if it's a Set then you need to use the deviceList.size property.

但是，第一个for循环有一个更兼容的版本，它是forEach()函数(可在

However, there is a more compatible version of your first for loop which is the forEach() function (which is available on Array and Set), like this:

deviceList.forEach(function (item) {
  result.push({"deviceName": item});
});

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