javascript - javascript中push/unshift的if else条件

Question

我有这个 javascript 对象。

var infoHolder = {
 labels: [],
};

当我插入数据时，我希望在推送中有一个条件。如:

infoHolder.labels.push({
 label: 'testLabel',
 image: 'testImage',

 // Condition - Not working!
 if(true) {
 toString: function() { return this.label;}
 } else {
  toString: function() { return this.image;}
 }; 
});

有没有简单的解决方案？ fiddle https://jsfiddle.net/t9wqeakL/

Answer 1

也许是这样的:

var infoHolder = { labels: [] }

infoHolder.labels.push({
    label: 'testlabel',
    get image() {return true ? 'testImage' : 'somethingElse'},
    toString: function() {return this.label}
})

infoHolder.labels.forEach(function(d){ console.log(d.image) })

查看prop getters .

或者更有趣的是创建新的/扩展[].push:

function pushTo(target, condition, props){
    // add protection here  
    Array.prototype.push.call(target, condition ? props["label"] : props["image"])
    return target
}

var o = pushTo(infoHolder.labels, 1 == "1", {label: "testLabel", image: "testImage"})

console.log(o)