js code for traversing the properties of an object-JS Tutorial-php.cn

js code for traversing the properties of an object

高洛峰

Release： 2017-01-14 11:16:16

Original

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For example:

Function.prototype.addMethod=function(methodName,func){ 
if(!this.prototype[methodName]){ 
this.prototype[methodName]=func;//给原型增加方法，此方法会影响到该类型的实例上 
} 
return this.prototype;//返回原型，此类型实例可以进行链形调用 
} 
function CustomObject(name,value){ 
this.name=name || &#39;CustomeObject&#39;; 
this.value=value || 0; 
this.toString=function(){ 
return &#39;[name:&#39;+this.name+&#39;,value:&#39;+this.value+&#39;]&#39; 
} 
} 
CustomObject.addMethod(&#39;testFun&#39;,function(){}) 
var obj=new CustomObject(); 
var info=&#39;&#39;; 
for(var property in obj){ 
info+=property+" | "; 
} 
alert(info); // name | value | toString | testFun |

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But at this time for in also traverses the attributes inherited by the object from the prototype object. If you want to remove the properties it inherits, you can use the hasOwnProperty statement. Such as

Function.prototype.addMethod=function(methodName,func){ 
if(!this.prototype[methodName]){ 
this.prototype[methodName]=func;//给原型增加方法，此方法会影响到该类型的实例上 
} 
return this.prototype;//返回原型，此类型实例可以进行链形调用 
} 
function CustomObject(name,value){ 
this.name=name || &#39;CustomeObject&#39;; 
this.value=value || 0; 
this.toString=function(){ 
return &#39;[name:&#39;+this.name+&#39;,value:&#39;+this.value+&#39;]&#39; 
} 
} 
CustomObject.addMethod(&#39;testFun&#39;,function(){}) 
var obj=new CustomObject(); 
var info=&#39;&#39;; 
for(var property in obj){ 
if(!obj.hasOwnProperty(property)) continue; 
info+=property+" | "; 
} 
alert(info); // name | value | toString |

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For more js code related articles for traversing the properties of objects, please pay attention to the PHP Chinese website!