TypeScript前端学习（二）

前言

????????继续分享TypeScript的学习，也是笔记，前端大佬请忽略。

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一、typeScript的数据类型

????????typescript除了我们熟知的基本数据类型，新增加了元组（python里也有）、any、never等。

二、类型举例

var isSuccess:boolean = false;
var isComplete= new Boolean(1);
var isOk = Boolean(1);
console.log(typeof isSuccess);
console.log(typeof isComplete);
console.log(isComplete.valueOf(),typeof  isComplete.valueOf())
console.log(isOk,typeof isOk);

//整数
var num1:number = 1;
//浮点数
var num2:number = 3.14;
//二进制
var num3:number = 0b1010;
//八进制
var num4:number = 0o71;
//十六进制
var num5:number = 0x123;
//无穷大
var num6:number = Infinity;
//非数字
var num7:number = NaN;

var str1:string = "Hello";
var str2:string = 'World';

var str3:string = `str1 is ${str1}, str2 is ${str2}`;
console.log(str3);

var arr1:number[] = [1,2,3];
arr1.push(4);

var arr2:Array<number> = [1,2,3];

console.log(arr1.pop());
console.log(arr2.pop());

//元组
var tuple1:[string,number,boolean] = ["Hello",123,Boolean(1)];
tuple1[0] = "2";
tuple1.push(Boolean(1));

console.log(tuple1[0]);

//枚举
var mut = 2;
enum Color {Red,Green,Blue,grey = mut * 2 + 1}
var c:Color = Color.Red;
console.log(c);
console.log(Color.Blue);
console.log(Color.grey);

enum Result{
    Success,
    Error
}
console.log(Result);
console.log(Result[0]);
console.log(Result["Success"]);

var mt = 2;
enum Rank{
    A = "A",
    B = "B",
    C = mt * 2 + 1
}
console.log(Rank);

var some:any = 1;

some = "str";
console.log(some);

some = [1,2,3];
console.log(some);

function fun1():never{
    while (true) {

    }
}

function errorMsg(msg:string):never{
    throw new Error(msg);

}

var some: any;
some = "hello";

console.log(some);
console.log((<String>some).length);

var some1: number | string;
some1 = "word"
console.log(some1);
console.log((<string>some1).length);
//console.log((<boolean>some1));

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总结

????????这就是笔记，一些例子大家可以自己打打，运行看看效果