一、基础类型
布尔值：
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let isDone:boolean = false;
十进制：
1
let decLiteral:number = 6;
十六进制：
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let hexLiteral:number = 0xf00d;
二进制：
1
let binaryLiteral:number = 0b1010;
八进制：
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let octalLiteral:number = 0o744;
字符串：
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let name:string = "bob";
name = "smith";
二、模板字符串：${ expr }
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let name:string = "Gene";
let age:number = 37;
let sentence:string = "Hello,my name is ${ name }.I'll be ${ age + 1 } year old next month.";
let sentence:string = "Hello,my name is " + name + ".\n\n" + "I'll be " + (age + 1) + "years old next month.";
三、数组：
方式一：
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let list:number[] = [1,2,3];
方式二：
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let list:Array<number> = [1,2,3];
四、元组 Tuple：
定义元组：
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let x:[string, number]; 正确赋值：
x = ["hello", 10]; 错误赋值：
x = [10 , "hello"];
五、枚举：(默认从0开始为元素编号)
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enum Color {Red, Green, Blue};
let c: Color = Color.Green;
改成从1开始编号:
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enum Color {Red = 1, Green, Blue};
let c: Color = Color.Green;
任意值：
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let noSure:any = 4;
notSure = "maybe a string insted";
notSure = false;
数组：
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let list:any[] = [1,true,"free"];
list[1] = 100;
空值：
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function warnUser():void{
alert("This is my warning message");
}
六、const 声明：(被赋值后不能被改变)
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const numLivesForCat = 9;
七、解构数组：
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let input = [1,2];
let [first,second] = input;
console.log(first);
console.log(second);
在函数参数中使用：
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functionf([first,second]:[number,number]){
console.log(first);
console.log(second);
}
f(input);
对象解构：
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let o = {
a:"foo",
b:12,
c:"bar"
}
let [a,b] = o;
八、剩余变量…name的用法
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let [first,...rest] = [1,2,3,4];
console.log(first); //输出 1
console.log(rest); //输出 [ 2, 3, 4 ]
九、接口：
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interface LabelledValue{
label:string;
}
function printLabel(labelledObj: LabelledValue){
console.log(labelledObj.label);
}
let myObj = {size:10,label:"Size 10 Object"};
printLabel(myObj);
可选属性：（加？号）
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interface SquareConfig{
color?:string;
width?:number;
}
function createSquare(config:SquareConfig):{color: string; area:number}{
let newSquare = {color: "White",area:100};
if(config.color){
newSquare.color = config.color;
}
if(config.width){
newSquare.area = config.width * config.width;
}
return newSquare;
}
let mySquare = createSquare({color: "black"});
只读属性：
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interface Point{
readonly x:number;
readonly y:number;
}
let p1:Point = {x: 10,y: 20}; // 初始化后不能再赋值
十、类：
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class Greeter {
greeting: string;
constructor(message: string){
this.greeting = message;
}
greet(){
return "Hello," + this.greeting;
}
}
let greeter = new Greeter("world");
十一、继承：
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class Animal{
name:string;
constructor(theName:string){
this.name = theName;
}
move(distanceInMeters:number = 0){
console.log('${this.name} moved ${distanceInMeters}m.');
}
}
class Snake extends Animal{
constructor(name:string){
super(name);
}
move(distanceInMeters = 5){
console.log("Slithering...");
super.move(distanceInMeters);
}
}
class Horse extends Animl{
constructor(name:string){
super(name);
}
move(distanceInMeters = 45){
console.log("Gallop...");
super.move(distanceInMeters);
}
}
let sam = new Snake("Sammy the Python");
let tom:Animal = new Horse("Tommy the Palomino");
sam.move();
tom.move(34);
十二、访问修饰符：(默认为public)
public公有的：
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class Animal{
public name:string;
public construtor(theName:string){
this.name = theName;
}
public move(distanceInMeters: number){
console.log('${this.name} moved ${distanceInMeters}m.');
}
}
private私有的：
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class Animal{
private name:string;
constructor(theName:stirng){
this.name = theName;
}
}
new Animal("Cat").name;// 错误的使用，name属性是私有的
protected受保护的：
class Person{
protected name:string;
constructor(name:string){
this.name = name;
}
}
class Employee extends Person{
private department:string;
constructor(name:string,department:string){
super(name);
this.department = department;
}
public getElevatorPitch(){
return 'Hello,my name is ${this.name} and I Work in ${this.department}.';
}
}
let howard = new Employee("Howard","Sales");
console.log(howard.getElevatorPitch);
console.log(howard.name); //不能访问，只能在派生类中使用 可以在getElevatorPitch()中使用
十三、readonly 修饰符：
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class Octopus{
readonly name:string;
readonly numberOfLegs:number = 8;
constructor(theName:string){
this.name = theName;
}
}
let dad = new Octopus("Man with the 8 strong legs");
dad.name = "Man with the 3-piece suit";// 不能赋值，name属性是只读的，只能在声明是或构造函数里被初始化。
十四、getters/setters方法：
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let passcode = "secret passcode";
class Employee{
private _fullName:string;
get fullName():string{
return this._fullName;
}
set fullName(newName:string){
if(passcode && passcode == "secret passcode"){
this._fullName = newName;
}
else{
console.log("Error: Unauthorized update of employee!");
}
}
}
let employee = new Employee();
employee.fullName = "Bob Smith";
if(employee.fullName){
alert(employee.fullName);
}
十五、静态属性static，使用类名调用
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class Grid{
static origin = {x:0,y:0};
calculateDistanceFromOrigin(point:{x:number;y:number;}){
let xDist = (point.x - Grid.origin.x);
let yDist = (point.x - Grid.origin.y);
return Math.sqrt(xDist * yDist + yDist * yDist) / this.scale;
}
constructor(public scale:number){}
}
十六、泛型：
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function identity<T>(arg:T):T{
return arg;
} 使用：
let outpet = identity<string>("myString");
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