typescript的介绍这里就不提，之前文章中有，目前typescript还不能直接运行在浏览器中，所以需要使用compiler进行编译成JavaScript文件进行运行。
/*特性一：字符串新特性*/
/*1、多行字符串*/
var content = `aaa
bbb
ccc`;
*******************************************
编译出js为：var content = "aaa\nbbb\nccc";
*******************************************/*2、字符串模板*/
var myName = 'xuchg';
var getName = function(){
return 'xuchg';
};
console.log(`my name is ${myName}`);
console.log(`also ${getName()}`);
*******************************************编译出js为：var myName = 'xuchg';var getName = function () { return 'xuchg';};console.log("my name is " + myName);console.log("also " + getName());
*******************************************//构建HTML模板
console.log(`
<div>
<span>${myName}</span>
<span>${getName()}</span>
</div>
`);
*******************************************编译出js为：console.log("\n <div>\n <span>" + myName + "</span>\n <span>" + getName() + "</span>\n </div>\n");
*******************************************/*3、自动拆分字符串*/
function test(temp,name,age){
console.log(temp);
console.log(name);
console.log(age);
}
var myName1 = "xuchg";
var getAge = function(){
return 23;
}
test`hello my name is ${myName1} I am ${getAge()}`;
*******************************************编译出js为：function test(temp, name, age) { console.log(temp); console.log(name); console.log(age);}var myName1 = "xuchg";var getAge = function () { return 23;};(_a = ["hello my name is ", " I am ", ""], _a.raw = ["hello my name is ", " I am ", ""], test(_a, myName1, getAge()));
*******************************************/*二、参数新特性*/
var myName2:string = "xuchg";
//typescript类型推断
var alias = "hehe";
//报错
// alias = 12;
var alias1:any = "这是一个任意类型";
var age:number = 21;
var man:boolean = true;
function testReturn(name:string):string{
return "这是一个参数和返回值定义类型的方法";
}
//自定义类型
class Person{
name:string;
age:number;
}
var xcg:Person = new Person();
xcg.name = "xuchg";
xcg.age = 23;
*******************************************编译出js为：
var myName2 = "xuchg";//typescript类型推断var alias = "hehe";//报错// alias = 12;var alias1 = "这是一个任意类型";var age = 21;var man = true;function testReturn(name) { return "这是一个参数和返回值定义类型的方法";}//自定义类型var Person = (function () { function Person() { } return Person;}());var xcg = new Person();xcg.name = "xuchg";xcg.age = 23;
*******************************************/*2、参数默认值*/
var myName3:string = "xuchg";
function testVal(a:string,b:string,c:string="这是默认值"){
console.log(a);
console.log(b);
console.log(c);
}//注意：带默认值得参数要声明在最后
testVal("aaa","bbb","CCC");
testVal("aaa","bbb");
*******************************************编译出js为：var myName3 = "xuchg";function testVal(a, b, c) { if (c === void 0) { c = "这是默认值"; } console.log(a); console.log(b); console.log(c);} //注意：带默认值得参数要声明在最后
*******************************************
/*3、可选参数：？*/
function testChange(a:string,b?:string,c:string="这是默认值"){
console.log(a);
console.log(b.length);//注意：声明了可选参数需要在函数中进行处理，否则会出现错误，而且可选参数不能声明在必选参数的前面
console.log(c);
}
testChange("XXX");
*******************************************编译出js为：
function testChange(a, b, c) { if (c === void 0) { c = "这是默认值"; } console.log(a); console.log(b.length); //注意：声明了可选参数需要在函数中进行处理，否则会出现错误，而且可选参数不能声明在必选参数的前面 console.log(c);}testChange("XXX");
*******************************************
/*三、函数新特性*/
/*1、rest and spread操作符，就是用来声明任意数量的方法参数，相当于Java的可变参数*/
function rs1(...args){
args.forEach(function(arg){
console.log(arg);
})
}
rs1(1,2,3);
rs1(4,5,6,7,8,9);
*******************************************编译出js为：function rs1() { var args = []; for (var _i = 0; _i < arguments.length; _i++) { args[_i] = arguments[_i]; } args.forEach(function (arg) { console.log(arg); });}rs1(1, 2, 3);rs1(4, 5, 6, 7, 8, 9);
//另一种情况
function rs2(a,b,c){
console.log(a);
console.log(b);
console.log(c);
}
var args = [1,2];
// rs2(...args);
*******************************************
/*2、generator函数，控制函数的执行过程，手工暂停和恢复代码的执行，只支持ES6*/
function* doThing(){
console.log("start");
yield;
console.log("finish");
}
var func = doThing();
func.next();
func.next();
*******************************************编译出js为：function doThing() { return __generator(this, function (_a) { switch (_a.label) { case 0: console.log("start"); return [4 /*yield*/]; case 1: _a.sent(); console.log("finish"); return [2 /*return*/]; } });}var func = doThing();func.next();func.next();
*******************************************
/*3、destructuring析构表达式，是通过表达式将对象或数组进行拆解成任意数量的变量*/
function getStock(){
//返回一个对象
return {
nameVal:'xuchg',
ageVal:23
}
}
//以下为js中的写法，以作对比
var stock = getStock();
var name1 = stock.nameVal;
var age1 = stock.ageVal;
//typescript的写法
var {nameVal,ageVal} = getStock();
console.log(nameVal);
console.log(ageVal);
//析构表达式接受的变量名必须和返回对象的变量名相同
//析构表达式从数组中取值
var arr = [1,2,4];
var [num1,num2,...otherNum] = arr;
console.log(num1);
console.log(num2);
console.log(otherNum);
//用在方法上
function doSomeThing([num1,num2,...otherNum]){
console.log(num1);
console.log(otherNum);
}
doSomeThing(arr);//拆分参数变量
*******************************************编译出js为：
function getStock() { //返回一个对象 return { nameVal: 'xuchg', ageVal: 23 };}//以下为js中的写法，以作对比var stock = getStock();var name1 = stock.nameVal;var age1 = stock.ageVal;//typescript的写法var _b = getStock(), nameVal = _b.nameVal, ageVal = _b.ageVal;console.log(nameVal);console.log(ageVal);//析构表达式接受的变量名必须和返回对象的变量名相同//析构表达式从数组中取值var arr = [1, 2, 4];var num1 = arr[0], num2 = arr[1], otherNum = arr.slice(2);console.log(num1);console.log(num2);console.log(otherNum);//用在方法上function doSomeThing(_a) { var num1 = _a[0], num2 = _a[1], otherNum = _a.slice(2); console.log(num1); console.log(otherNum);}doSomeThing(arr); //拆分参数变量var _a;
*******************************************
