Returns this Number value. ThevalueOffunction is not generic; it throws aTypeErrorexception if itsthisvalue is not a Number or a Number object. Therefore, it cannot be transferred to other kinds of objects for use as a method. 原来Number有属于自身的原型valueOf方法,不是直接从Object.prototype上...
Returns this Number value. The valueOf function is not generic; it throws a TypeError exception if its this value is not a Number or a Number object. Therefore, it cannot be transferred to other kinds of objects for use as a method. 原来Number有属于自身的原型valueOf方法,不是直接从Object....
JS中令人发指的valueOf方法介绍 JS中令⼈发指的valueOf⽅法介绍 彭⽼湿近期⽉报⾥提到了valueOf⽅法，兴致来了翻了下ECMA5⾥关于valueOf⽅法的介绍，如下：15.2.4.4 Object.prototype.valueOf ( )When the valueOf method is called, the following steps are taken:1. Let O be the result...
You rarely need to invoke the valueOf method yourself; JavaScript automatically invokes it when encountering an object where a primitive value is expected. 我想纠正一下题主的想法: 1. toString()和valueOf()完全是做两件事的函数 2. valueOf()之所以很少用到,如上面所说的,因为js会在需要的时候会自...
js对象检查是否定义了toString 如果toString()与Object相同,您可以检查其原型: TestClass.prototype.toString === Object.prototype.toString 或者,通过实例: // preferred method:Object.getPrototypeOf(testClassInstance).toString === Object.prototype.toString// alternative accessing __proto__ directly:testClassInst...
ThevalueOf()method does not change the original array. fruits.valueOf()returns the same asfruits. Syntax array.valueOf() Parameters NONE Return Value TypeDescription An arrayThevalueOf()method returns itself! Array Tutorials: Array Tutorial ...
If the object has no primitive value,valueOf()returns the object itself. ThevalueOf()method does not change the original object. Note fruits.valueOf()returns the same asfruits. Syntax object.valueOf() Parameters NONE Return Value The primitive value of an object. ...
If happens in boolean context, likeif(obj),while(obj)etc. Object may not implement such conversion on their own, there is no magic method. Instead, there is a hardcoded table of conversions: ' Unlike many programming languages (for example PHP),"0"istruein JavaScript. ...
JavaScript : valueOf() method JS Code var value = new Array('$.1', '$.2', '$.3'); var fruits = new Array("Orange", "Apple", "Banana", "Chery",value); var newParagraph = document.createElement("p"); //creates a new paragraph element var...
[Microsoft.JScript.JSFunction(Microsoft.JScript.JSFunctionAttributeEnum.HasThisObject, Microsoft.JScript.JSBuiltin.String_valueOf)]publicstaticobjectvalueOf(objectthisob); Parameters thisob Object The object that this method is acting upon. Returns ...