#6 Generic

 

함수 매개변수 Generic

// Generic
function getSize<T>(arr: T[]): number {
    return arr.length;
}

const arr1 = [1,2,3];
getSize<number>(arr1); // 3

const arr2 = ["a","b","c"];
getSize<string>(arr2); // 3

const arr3 = [false, true, false];
getSize<boolean>(arr3); // 3

const arr4 = [{}, {},{name: "Tom"}];
getSize<object>(arr4); // 3

 

interface Generic 

// 인터페이스 맴버변수 타입을 generic으로 선언하는 예
interface Mobile<T> {
    name: string;
    price: number;
    option: T; // string, object... 입력가능
}

const m1: Mobile<object> = {
    name: "s21",
    price: 1000,
    option: {
        color: "red",
        coupon: false,
    },
};

const m2: Mobile<{color: string; coupon: boolean}> = {
    name: "s21",
    price: 1000,
    option: {
        color: "red",
        coupon: false,
    },
};

const m3: Mobile<string> = {
    name: "s20",
    price: 900,
    option: "good",
};​

 

// Generic

interface User {
    name: string;
    age: number;
}

interface Car {
    name: string;
    color: string;
}

interface Book {
    price: number;
}

const user: User = {name: "a", age:10};
const car : Car = {name:"bmw", color:"red"};
const book : Book = {price: 3000};

// 함수에 전달되는 객체를 Generic으로 전달
function showName<T extends {name: string}>(data: T): string {
    return data.name;
}

showName(user);
showName(car);
// showName(book);