Migrated issue from codeplex: https://typescript.codeplex.com/workitem/507 Currently typescript will type the "this" pointer in function callbacks as "any." Arrow syntax lets us capture "this" from the outer scope, and this can enable pr...
function fn(x: string): void; // This overload signature is not compatible with its implementation signature. function fn(x: boolean) {} function fn(x: string): string; // Return type isn't right function fn(x: number): boolean; This overload signature is not compatible with its imple...
function add(x: number, y: number): number { return x + y; } let myAdd = function(x: number, y: number): number { return x + y; };我们可以给每个参数添加类型之后再为函数本身添加返回值类型。 TypeScript能够根据返回语句自动推断出返回值类型,因此我们通常省略它。
typeThisType={name:string};// 指定this的类型functioneating(this:ThisType,message:string){console.log(this.name+" eating",message);}constinfo={name:"why",eating:eating,};// 隐式绑定info.eating("哈哈哈");// 显示绑定eating.call({name:"kobe"},"呵呵呵")eating.apply({name:"james"},["嘿...
We can get this functionality in TypeScript by adding a ? to the end of parameters we want to be optional. Any optional parameters must follow required parameters. 代码语言:javascript 代码运行次数:0 复制Cloud Studio 代码运行 function buildName(firstName: string, lastName?: string) { if (last...
接下来我们使用 TypeScript 的箭头函数。把function()替换为() =>: varshape={name:"rectangle",popup:function(){console.log('This inside popup(): '+this.name);setTimeout(()=>{console.log('This inside setTimeout(): '+this.name);console.log("I'm a "+this.name+"!");},3000);}};sh...
从TypeScript 2.0 开始,在函数和方法中我们可以声明this的类型,实际使用起来也很简单,比如: functionsayHello(this:void){// this: void:表示在函数体内不允许使用this} 在上面的 sayHello 函数中,this 参数是伪参数,它位于函数参数列表的第一位。为什么说 this 参数是伪参数呢?因为以上的 sayHello 函数经过编译后...
//拷贝静态属性5function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };6return extendStatics(d, b);7};8return function (d, b) { // 拷贝静态属性9extendStatics(d, b); //拷贝静态函数10function __() { this.constructor = d; } ...
__proto__ = b; }) || function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; }; return extendStatics(d, b); }; return function (d, b) { extendStatics(d, b); function __() { this.constructor = d; } d.prototype = b === null ? Object....
TypeScript是Microsoft公司注册商标。 TypeScript具有类型系统,且是JavaScript的超集。 它可以编译成普通的JavaScript代码。 TypeScript支持任意浏览器,任意环境,任意系统并且是开源的。 TypeScript目前还在积极的开发完善之中,不断地会有新的特性加入进来。 因此本手册也会紧随官方的每个commit,不断地更新新的章节以及修改...