与其他语言相比,函数的 this 关键字在 JavaScript 中的表现略有不同,此外,在严格模式和非严格模式之间也会有一些差别。
这里我们在三种不同情境去打印”this”,分别是在函数的最外层(outer environment)直接去执行;使用fuction statement去执行;使用function expression去执行(如果还不清楚function statement和function expression的差别,可以参考注1)。 结果会发现,这三个”this”都会指向同样的对象,也就是global environment的window object (...
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代码语言:javascript 代码运行次数:0 AI代码解释 $func=function($say){echo $this->name,':',$say,PHP_EOL;};$func('good');// Fatal error: Uncaught Error: Using $this when not in object context 在这个匿名函数中,我们使用了 \$this->name 来获取当前作用域下的 $name 属性,可是,这个 $this ...
When the arrow function has only 1 statement, you could even omit the return keyword.An arrow function is anonymous, but its name can be inferred. It doesn't have a lexical function name (which would be useful for recursion, detaching event handlers)....
16. What is the use of this JavaScript statement? Submit It will write "Submit" on the current Window It will print the content of the current page It will write the content of the current page in the browser’s console None of the above Answer:B) It will print...
宿主对象(host Objects):由JavaScript宿主环境提供的对象,它们的行为完全由宿主环境决定。 内置对象(Built-in Objects):由JavaScript语言提供的对象。 固有对象(Intrinsic Objects ):由标准规定,随着JavaScript运行时创建而自动创建的对象实例。 原生对象(Native Objects):可以由用户通过Array、RegExp等内置构造器或者特殊语法...
But you may have noticed the dollar sign ($) before it. Now, whenever there is a dollar sign ($) in front then it is a part of jQuery. Hence, when we represent$(this)for an element, this must be considered a jQuery statement. ...
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Again we’re seeing some new syntax, this time in the form of afor-ofstatement. This is used to iterate through the results of a generator function. Since this function is lazy evaluated we don’t have array indexers or anything on it, instead we have anextmethod which tells it we wa...