typescript interface function

1interface IEmployee {
2    empCode: number;
3    empName: string;
4    getSalary: (number) => number; // arrow function
5    getManagerName(number): string; 
6}
7

1interface IPerson {
2  name: string
3  age: number
4  hobby?: string[]
5}
6
7class Person implements IPerson {
8  name: string
9  age: number
10  hobby?: string[]
11
12  constructor(name: string, age: number, hobby: string[]) {
13    this.name = name
14    this.age = age
15    this.hobby = hobby
16  }
17}
18
19const output = new Person('john doe', 23, ['swimming', 'traveling', 'badminton'])
20console.log(output)
21

1// https://stackoverflow.com/a/41967120
2// `I` Prefix not recommended : 
3// Ref : https://stackoverflow.com/a/41967120, 
4//       https://github.com/Microsoft/TypeScript/wiki/Coding-guidelines
5interface SquareConfig {
6  color?: string;
7  width?: number;
8  [propName: string]: any;
9}
10
11interface StringArray {
12  [index: number]: string;
13}
14 
15let myArray: StringArray;
16myArray = ["Bob", "Fred"];
17 
18let myStr: string = myArray[0];
19

1interface Foo {
2    bar: string;
3    qux: number;
4}
5// Creates object implementing interface:
6const MyFoo = <Foo> {
7    bar: "Hello",
8    qux: 7
9}
10// Or:
11const MyFoo: Foo = {
12    bar: "Hello",
13    qux: 7
14}

1type ErrorHandler = (error: IError) => void // type for only one function
2// or
3interface IErrorHandler {
4  ErrorHander: (error: IError) => void
5}
6    
7// IError Interface if interest
8interface IError {
9  error: string;
10  status: number;
11  message: string;
12}

1interface Task{
2    name: String; //property
3    run(arg: any):void; //method
4}
5
6class MyTask implements Task{
7    name: String;
8    constructor(name: String) {
9        this.name = name;
10    }
11	run(arg: any): void {
12        console.log(`running: ${this.name}, arg: ${arg}`);
13    }
14}
15
16let myTask: Task = new MyTask('someTask');
17myTask.run("test");