function merge<T extends object, U extends object>(objA: T, objB: U) {
    return {...objA, ...objB};
}

const mergedObj = merge({ name: 'Max', hobbies: ['Sports'] }, { age: 30 });
console.log(mergedObj);

function countAndDescribe<T extends Lengthy>(element: T) {
    let descriptionText = 'Got no value.';
    if (element.length === 1) {
        descriptionText = 'Got 1 element';
    } else if (element.length > 1) {
        descriptionText = 'Got ' + element.length + ' elemets.';
    }
    return [element, descriptionText];
}

console.log(countAndDescribe(['Sports', 'Cooking']));

keyof 예)

function extractAndConvert<T extends object, U extends keyof T>(obj: T, key: U) {
    return 'Value: ' + obj[key];
}

console.log(extractAndConvert({name: 'Max' }, 'name'));

제네릭 클래스

class DataStorage<T extends number | string | boolean> {
    private data: T[] = [];

    addItem(item: T) {
        this.data.push(item);
    }

    removeItem(item: T) {
        this.data.splice(this.data.indexOf(item), 1);
    }

    getItems() {
        return [...this.data];
    }
}

const textStorage = new DataStorage<string>();
textStorage.addItem('Max');
textStorage.addItem('Manu');
textStorage.removeItem('Max');
console.log(textStorage.getItems());

const numberStorage = new DataStorage<number>();

// const objectStorage = new DataStorage<object>();
// objectStorage.addItem({ name: 'Max' });
// objectStorage.addItem({ name: 'Manu' });
// objectStorage.removeItem({ name: 'Manu' });
// console.log(objectStorage.getItems());