What the this-keyword allows us to do, is it allows us to reuse functions with different contexts, or in other words it allows us to decide which objects should be focal when invoking a function or a methods. I
'this' Keyword & Function References The 'this' keyword can lead to a lot of confusion in JS. So can function calls without parenthesis. What's the idea behind this.someFunction.bind(this)? Created by Maximilian SchwarzmüllerSeptember 12, 2018 Watch Video ...
Show inner this 在这种情况下,内部函数的 this 指向globalThis 对象(即非严格模式下,调用的函数未设置 this 时指向的默认对象)。 类中的绑定方法 和其他普通函数一样,方法中的 this 值取决于它们如何被调用。有时,改写这个行为,让类中的 this 值总是指向这个类实例会很有用。为了做到这一点,可在构造函数中...
you're going to find that whenever you get in these situation of trying to figure out what the this-keyword is, the very first thing you should do is look at when the function was invoked, and look if there's anything to the left of the dot, because if there is, that's what this...
this是Javascript语言的一个关键字。 它代表函数运行时,自动生成的一个内部对象,只能在函数内部使用。比如, function test(){ this.x = 1; } 随着函数使用场合的不同,this的值会发生变化。但是有一个总的原则,那就是this指的是,调用函数的那个对象。
fullName :function() { returnthis.firstName+" "+this.lastName; } }; Try it Yourself » What isthis? In JavaScript, thethiskeyword refers to anobject. Thethiskeyword refers todifferent objectsdepending on how it is used: In an object method,thisrefers to theobject. ...
JavaScript this Keyword We usethiskeyword in an object method to access a property of the same object. For example, // person objectconstperson = {name:"John",age:30,// methodintroduce:function(){ console.log(`My name is${this.name}and I'm${this.age}years old.`); ...
thethiskeyword refers to anobject. 但究竟指向哪个object要看this在哪里被调用或者如何被调用 在对象方法object中,指向对象 单独调用时,指向global 在函数function中,严格模式下为undefined,非严格模式下指向global 在事件event中,指向接受该事件的元素(比如一个监听事件addEventListener,指向绑定该事件的元素) ...
http://www.ruanyifeng.com/blog/2010/04/using_this_keyword_in_javascript.html 分情况讨论。 情况一:纯粹的函数调用 这是函数的最通常用法,属于全局性调用,因此this就代表全局对象Global。 var x = 1; function test(){ this.x = 0; ...
而在javascript中，函数的调用一共有4种方式：Function Invocation Pattern诸如`foo()`的调用形式被称为...