起因：
想要简化几处反复的代码块，代码形如下图
var xxxList = data.xxxList; if (!this.aaaLayer) { this.aaaLayer = new AAALayer(xxxList); this.aaaLayer.setAnchorPoint(0.5, 0.5); this.background.addChild(this.aaaLayer, 3); } else { this.aaaLayer.remove(); this.aaaLayer.layout(xxxList); } if (!this.bbbLayer) { this.bbbLayer = new BBBLayer(xxxList); this.bbbLayer.setAnchorPoint(0.5, 0.5); this.background.addChild(this.bbbLayer, 3); } else { this.bbbLayer.remove(); this.bbbLayer.layout(xxxList); } if (!this.cccLayer) { this.cccLayer = new CCCLayer(xxxList); this.cccLayer.setAnchorPoint(0.5, 0.5); this.background.addChild(this.cccLayer, 3); } else { this.cccLayer.remove(); this.cccLayer.layout(xxxList); } if (!this.dddLayer) { this.dddLayer = new DDDLayer(xxxList); this.dddLayer.setAnchorPoint(0.5, 0.5); this.background.addChild(this.dddLayer, 3); } else { this.dddLayer.remove(); this.dddLayer.layout(xxxList); }
因为反复度太高，看着切实好受，于是就想整合在一起，然而因为每个Layer都要对应一个结构Layer，通常会须要用条件判断来进行划分，然而这样以来不免又写的很长，所以我决定用两个数组别离寄存指标Layer和结构器Layer,于是就有了上面的整合函数：
compressFunc: function (xxxList) { var targetLayer = [ "aaaLayer", "bbbLayer", "cccLayer", "dddLayer" ]; var constructLayer = [ AAALayer, BBBLayer, CCCLayer, DDDLayer ]; targetLayer.forEach(function (item, index){ this[item] = new constructLayer[index](xxxList[index].data); this[item].setAnchorPoint(0.5, 0.5); this.background.addChild(this[item], 3); }.bind(this)); },
如此一来就能够完满的用forEach和this[item]来防止很长的条件判断了，鉴于平时我都不会用到this[xxx]这种构造，所以权且记录下来，万一当前就变成了一个Bug呢