A minimalist typescript cheatsheet to get started quickly
// Install typescript
npm install -g concurrently lite-server typescript
// Run the .ts
tsc typescript-cheatsheet --watch
// In another terminal window
node typescript-cheatsheet
| export {}; | |
| let message = "Hello"; | |
| console.log(message); | |
| let isBeginner: boolean = true; | |
| let total: number = 0; | |
| let name: string = "Joe"; | |
| let sentence: string = `My name is ${name}`; | |
| console.log(sentence); | |
| let list01: number[] = [1, 2, 3]; | |
| let list02: Array<number> = [1, 2, 3]; | |
| let person01: [string, number] = ["Bob", 30]; | |
| enum Color { | |
| Reg, | |
| Green, | |
| Blue | |
| } | |
| let c: Color = Color.Green; | |
| console.log(c); | |
| let myVariable: any = 10; | |
| function hasName(obj: any): obj is { name: string } { | |
| return !!obj && typeof obj === "object" && "name" in obj; | |
| } | |
| if (hasName(myVariable)) { | |
| console.log(myVariable.name); | |
| } | |
| let multiType: number | boolean; | |
| multiType = 10; | |
| multiType = true; | |
| function add(num1: number, num2?: number): number { | |
| return num1 + num2; | |
| } | |
| add(5); | |
| function fullName(person: { firstName: string; lastName: string }): void { | |
| console.log(person.firstName, person.lastName); | |
| } | |
| let p = { | |
| firstName: "Bob", | |
| lastName: "Dylan" | |
| }; | |
| fullName(p); | |
| interface Person { | |
| firstName: string; | |
| lastName: string; | |
| address?: string; | |
| } | |
| function user(person: Person): void { | |
| console.log(person.firstName, person.lastName); | |
| } | |
| user({ firstName: "Johnny", lastName: "Cash" }); | |
| class Employee { | |
| employeeName: string; | |
| // public employeeName: string; // full access | |
| // private employeeName: string; // no access | |
| // protected employeeName: string; // acess within a derived class | |
| constructor(name: string) { | |
| this.employeeName = name; | |
| } | |
| greet() { | |
| console.log("Good morning", this.employeeName); | |
| } | |
| } | |
| let emp1 = new Employee("Kenny"); | |
| console.log(emp1.employeeName); | |
| emp1.greet(); | |
| class Manager extends Employee { | |
| constructor(managerName: string) { | |
| super(managerName); | |
| } | |
| delegateWork() { | |
| console.log("Manager delegating tasks"); | |
| } | |
| } | |
| let m1 = new Manager("Bruce"); | |
| m1.delegateWork(); | |
| m1.greet(); | |
| console.log(m1.employeeName); |