- How to use Explicit Type (let a : string).
- How to use Explicit Type with Union Type (let a : string | number).
- How to use Dynamic/Any Types in TypeScript (let a : any).
- How to use Function Type (let myFunction : Function).
- How to use Optional parameter in a function (a?:string);
- How to use default value in parameter in a function (a:string = "Hasibul");
- How to define return and void in a function
let myFunction : () => void // no return required.
let funSing1: (a: number, b: number) => number; // that means it have a retuen type with number we can change the parameter property name when we are using this function. funSing1 = (x: number, y: number) => { return x * y; };
funSing1(5, 6);
let calculation: (x: number, y: number, z: string) => number;
calculation = (x: number, y: number, z: string) => { if (z === "add") { return x + y; } else { return x - y; } }; calculation(5, 6, "add");
let myFunction : (a: number, b: number) => number // return required.
it means we can create our own type for reduce repeating code
const myDetails = (
id: string | number,
details: { name: string; age: number }
) => {
console.log(my name is ${details.name} and my id is ${id});
};
myDetails(12, {name:"hasibul", age: 24})
type stringOrNumber = string | number;
type detailsInfo = { name: string; age: number };
const myDetails1 = (id: stringOrNumber, details: detailsInfo) => {
console.log(my name is ${details.name} and my id is ${id});
};# TypeScript-Day-2
- How to create class with explicit and union types, and how to use class as a class type in a array.