[Javascript] this in Function Calls In most cases, the value of a function'sthisargument is determined by how the function is called. This lesson explains whatthisrefers to when we call plain function. Marius points out how functions behave differently in strict and non-strict mode."use stric...
[Javascript] this in Function Calls In most cases, the value of a function'sthisargument is determined by how the function is called. This lesson explains whatthisrefers to when we call plain function. Marius points out how functions behave differently in strict and non-strict mode."use stric...
1、理解 function 的 apply() 方法。 “The apply() method calls a function with a given this value and arguments provided as an array.” apply 什么呢? 把当前的对象(只要类型是 object 即可) apply 给 function,作为该 function 的 this 对象。 apply 方法针对的是将要执行的 function 的 this。 它...
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....
代码语言:javascript 代码运行次数:0 运行 AI代码解释 functionexecute(){'use strict';functionconcat(str1,str2){// the strict mode is enabled tooconsole.log(this===undefined);// => truereturnstr1+str2;}console.log(this===undefined);// => true// concat() is invoked as a function in st...
}Person.prototype.getName=function(){returnthis.name; }varlzh =newPerson("lzh");console.log(lzh.getName());// lzh Apply、call 调用模式 因为JavaScript 是一门函数式的面向对象编程语言,所以函数可以拥有方法。 每个函数都包含两个非继承而来的方法:apply()和 call()。这两个方法的用途都是在特定的作...
myNumber = 20; // add 'myNumber' property to global object return a + b; } // sum() is invoked as a function // this in sum() is a global object (window) sum(15, 16); // => 31 window.myNumber; // => 20 当调用 sum(15, 16) 的时候,JavaScript 会自动将 this 指向全局...
Over the years, I've seen a lot of confusion about JavaScript function invocation. In particular, a lot of people have complained that the semantics ofthisin function invocations is confusing. In my opinion, a lot of this confusion is cleared up by understanding the core function invocation pr...
In JavaScript,constructor functionsare used to create objects. When a function is used as a constructor function,thisrefers to the object inside which it is used. For example, functionPerson(){this.name ='Jack';console.log(this); }letperson1 =newPerson();console.log(person1.name); ...
ES5 为了使 JavaScript 运行在更有限制性的环境而添加了严格模式，严格模式为了消除安全隐患，禁止了 this 关键字指向全局对象。var x = 1function fn() { console.log(this); // Window 全局对象 console.log(this.x); // 1}fn(); 使用严格模式后："use strict" // 使用严格模式var...