طريقتا Join وSplit

array.join([separator])
string.split([separator])

const fruits = ['apple', 'banana', 'orange'];
const str = fruits.join(', ');
console.log(str); // "apple, banana, orange"

const sentence = "Hello World";
const words = sentence.split(' ');
console.log(words); // ['Hello', 'World']

const fruits = ['apple', 'banana', 'orange'];
console.log(fruits.join('')); // “applebananaorange”
console.log(fruits.join('-')); // "apple-banana-orange"
const date = "2023-05-15";
console.log(date.split('-')); // ['2023', '05', '15']