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...
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call bind Thebind()method creates a new function that, when called, has itsthiskeyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called....
In JavaScript, as in most object-oriented programming languages,thisis a special keyword that is used within methods to refer to the object on which a method is being invoked. ——jQuery Fundamentals (Chapter 2), by Rebecca Murphey 值得注意,该关键字在Javascript中和执行环境,而非声明环境有关。
Learn how the JavaScript “this” keyword behaves inside of function declarations and expressions, even when nested 10 levels deep. In the article: The JavaScript “this” Keyword Deep Dive: An Overview, we discussed a number of scenarios in which the JavaScript “this” Keyword has different me...
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)?
「The this keyword evaluates to the value of the ThisBinding of the current execution context.」「this 这个关键字代表的值为当前执行上下文的ThisBinding。」然后再来看看MDN 对this 的定义：「In most cases, the value of this is determined by how a function is called.」「在大多数的情况下，this ...
function bar() { alert(this); } bar(); // global - 因为bar方法被调用时属于 global 对象 var foo = { baz: function() { alert(this); } } foo.baz(); // foo - 因为baz()方法被调用时术语foo对象 如果this就这么简单,那上面的代码就足够了。我们可以进一步使事情变得复杂,通过不同的调用语法...
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; ...
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. ...