Typescript 入门

大神链接

• 字符串

let str:string = 'Hello World!';

• 数值类型

let num:number = 18;

• bool类型

let boolValue:boolean = true;

• undefined

let undefinedValue:undefined = undefined;

• null

let nullValue:null = null;

• 对象

let obj:object = {x:1};

• 数组

let arr:string[] = ["1","2","3"];
let array:Array<string> = ["Roy","Ei"];

• 联合类型数组

let arr:(number|string)[] = [];
arr = [1,"2",3,"4"];

• 对象数组

interface ArrayObj {
    name:string,
    age:number
}
let array:ArrayObj[] = [{name:'Roy',age:18}];

• 函数

function sum(x:number,y:number):number {
    return x + y;
}

• 接口定义函数

interface InterfaceFunc {
    sum(x:number,y:number):boolean;
}

• 可选参数

function buildName(firstName:string,lastName?:string) {
    if (lastName) {
        return firstName + " " + lastName;
    } else {
        return firstName;
    }
}
let CaptainRoy = buildName("Captain","Roy");
let Roy = buildName("Roy");

• 默认参数

function buildName(firstName:string,lastName:string='Roy') {
    return firstName + " " + lastName;
}
let CapatinRoy = buildName("Captain","Cat");
let Roy = buildName("Captain");