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mirror of https://github.com/adambard/learnxinyminutes-docs.git synced 2025-08-07 23:37:32 +02:00

Fix formatting, close #990

Cleaned up mixed tabs/spaces
Wrapped lines at 80 characters
Fixed incorrect comment regarding property name
This commit is contained in:
Nolan Prescott
2015-03-10 15:09:35 -05:00
parent 104ffc3608
commit 2ae3d41c27

View File

@@ -14,100 +14,111 @@ This article will focus only on TypeScript extra syntax, as oposed to [JavaScrip
To test TypeScript's compiler, head to the [Playground] (http://www.typescriptlang.org/Playground) where you will be able to type code, have auto completion and directly see the emitted JavaScript. To test TypeScript's compiler, head to the [Playground] (http://www.typescriptlang.org/Playground) where you will be able to type code, have auto completion and directly see the emitted JavaScript.
```js ```js
//There are 3 basic types in TypeScript // There are 3 basic types in TypeScript
var isDone: boolean = false; var isDone: boolean = false;
var lines: number = 42; var lines: number = 42;
var name: string = "Anders"; var name: string = "Anders";
//..When it's impossible to know, there is the "Any" type // When it's impossible to know, there is the "Any" type
var notSure: any = 4; var notSure: any = 4;
notSure = "maybe a string instead"; notSure = "maybe a string instead";
notSure = false; // okay, definitely a boolean notSure = false; // okay, definitely a boolean
//For collections, there are typed arrays and generic arrays // For collections, there are typed arrays and generic arrays
var list: number[] = [1, 2, 3]; var list: number[] = [1, 2, 3];
//Alternatively, using the generic array type // Alternatively, using the generic array type
var list: Array<number> = [1, 2, 3]; var list: Array<number> = [1, 2, 3];
//For enumerations: // For enumerations:
enum Color {Red, Green, Blue}; enum Color {Red, Green, Blue};
var c: Color = Color.Green; var c: Color = Color.Green;
//Lastly, "void" is used in the special case of a function not returning anything // Lastly, "void" is used in the special case of a function returning nothing
function bigHorribleAlert(): void { function bigHorribleAlert(): void {
alert("I'm a little annoying box!"); alert("I'm a little annoying box!");
} }
//Functions are first class citizens, support the lambda "fat arrow" syntax and use type inference // Functions are first class citizens, support the lambda "fat arrow" syntax and
//All examples are equivalent, the same signature will be infered by the compiler, and same JavaScript will be emitted // use type inference
var f1 = function(i: number) : number { return i * i; }
var f2 = function(i: number) { return i * i; } //Return type infered
var f3 = (i : number) : number => { return i * i; }
var f4 = (i: number) => { return i * i; } //Return type infered
var f5 = (i: number) => i * i; //Return type infered, one-liner means no return keyword needed
//Interfaces are structural, anything that has the properties is compliant with the interface // The following are equivalent, the same signature will be infered by the
// compiler, and same JavaScript will be emitted
var f1 = function(i: number) : number { return i * i; }
// Return type inferred
var f2 = function(i: number) { return i * i; }
var f3 = (i : number) : number => { return i * i; }
// Return type inferred
var f4 = (i: number) => { return i * i; }
// Return type inferred, one-liner means no return keyword needed
var f5 = (i: number) => i * i;
// Interfaces are structural, anything that has the properties is compliant with
// the interface
interface Person { interface Person {
name: string; name: string;
//Optional properties, marked with a "?" // Optional properties, marked with a "?"
age?: number; age?: number;
//And of course functions // And of course functions
move(): void; move(): void;
} }
//..Object that implements the "Person" interface // Object that implements the "Person" interface
var p : Person = { name: "Bobby", move : () => {} }; //Can be treated as a Person since it has the name and age properties // Can be treated as a Person since it has the name and move properties
//..Objects that have the optional property: var p : Person = { name: "Bobby", move : () => {} };
// Objects that have the optional property:
var validPerson : Person = { name: "Bobby", age: 42, move: () => {} }; var validPerson : Person = { name: "Bobby", age: 42, move: () => {} };
var invalidPerson : Person = { name: "Bobby", age: true }; //Is not a person because age is not a number // Is not a person because age is not a number
var invalidPerson : Person = { name: "Bobby", age: true };
//..Interfaces can also describe a function type // Interfaces can also describe a function type
interface SearchFunc { interface SearchFunc {
(source: string, subString: string): boolean; (source: string, subString: string): boolean;
} }
//..Only the parameters' types are important, names are not important. // Only the parameters' types are important, names are not important.
var mySearch: SearchFunc; var mySearch: SearchFunc;
mySearch = function(src: string, sub: string) { mySearch = function(src: string, sub: string) {
return src.search(sub) != -1; return src.search(sub) != -1;
} }
//Classes - members are public by default // Classes - members are public by default
class Point { class Point {
//Properties // Properties
x: number; x: number;
//Constructor - the public/private keywords in this context will generate the boiler plate code // Constructor - the public/private keywords in this context will generate
// for the property and the initialization in the constructor. // the boiler plate code for the property and the initialization in the
// In this example, "y" will be defined just like "x" is, but with less code // constructor.
//Default values are also supported // In this example, "y" will be defined just like "x" is, but with less code
constructor(x: number, public y: number = 0) { // Default values are also supported
this.x = x;
} constructor(x: number, public y: number = 0) {
this.x = x;
//Functions }
dist() { return Math.sqrt(this.x * this.x + this.y * this.y); }
// Functions
//Static members dist() { return Math.sqrt(this.x * this.x + this.y * this.y); }
static origin = new Point(0, 0);
// Static members
static origin = new Point(0, 0);
} }
var p1 = new Point(10 ,20); var p1 = new Point(10 ,20);
var p2 = new Point(25); //y will be 0 var p2 = new Point(25); //y will be 0
//Inheritance // Inheritance
class Point3D extends Point { class Point3D extends Point {
constructor(x: number, y: number, public z: number = 0) { constructor(x: number, y: number, public z: number = 0) {
super(x, y); //Explicit call to the super class constructor is mandatory super(x, y); // Explicit call to the super class constructor is mandatory
} }
//Overwrite // Overwrite
dist() { dist() {
var d = super.dist(); var d = super.dist();
return Math.sqrt(d * d + this.z * this.z); return Math.sqrt(d * d + this.z * this.z);
} }
} }
//Modules, "." can be used as separator for sub modules // Modules, "." can be used as separator for sub modules
module Geometry { module Geometry {
export class Square { export class Square {
constructor(public sideLength: number = 0) { constructor(public sideLength: number = 0) {
@@ -120,32 +131,32 @@ module Geometry {
var s1 = new Geometry.Square(5); var s1 = new Geometry.Square(5);
//..Local alias for referencing a module // Local alias for referencing a module
import G = Geometry; import G = Geometry;
var s2 = new G.Square(10); var s2 = new G.Square(10);
//Generics // Generics
//..Classes // Classes
class Tuple<T1, T2> { class Tuple<T1, T2> {
constructor(public item1: T1, public item2: T2) { constructor(public item1: T1, public item2: T2) {
} }
} }
//..Interfaces // Interfaces
interface Pair<T> { interface Pair<T> {
item1: T; item1: T;
item2: T; item2: T;
} }
//..And functions // And functions
var pairToTuple = function<T>(p: Pair<T>) { var pairToTuple = function<T>(p: Pair<T>) {
return new Tuple(p.item1, p.item2); return new Tuple(p.item1, p.item2);
}; };
var tuple = pairToTuple({ item1:"hello", item2:"world"}); var tuple = pairToTuple({ item1:"hello", item2:"world"});
//Including references to a definition file: // Including references to a definition file:
/// <reference path="jquery.d.ts" /> /// <reference path="jquery.d.ts" />
``` ```