JAVASCRIPT STEP 7 - DATE

★ DATE

• 시간을 다루는 내장 객체
• 현재 시각

var now = new Date(); //new 생성자함수()
console.log(now);
console.log(now.toString); //javascript는 자동으로 toString을 해줌

• 요소 추출

console.log(now.getYear());      	//123           
console.log(now.getFullYear());		//2023
console.log(now.getMonth());		//3(0부터)
console.log(now.getDate());		//21
console.log(now.getDay());		//5(일(0)~토(6))
console.log(now.getHours());		//10
console.log(now.getMinutes());		//20
console.log(now.getSeconds());		//20
console.log(now.getMilliseconds());	//135
console.log(now.getTime());		//1682040020135

• 출력 > %tF, %tT, %tA

console.log(now.toLocaleString()); //2023. 4. 21. 오전 10:27:19
console.log(now.toLocaleDateString()); //2023. 4. 21.
console.log(now.toLocaleTimeString()); // 오전 10:27:19

• 특정 시각 만들기

var Christmas = new Date();

Christmas.setFullYear(2023);
Christmas.setMonth(11);
Christmas.setDate(25);

console.log(Christmas.toLocaleDateString()); //2023. 12. 25.

• 연산
• 시각 - 시각

console.log(christmas - now); //21427200001ms

console.log((christmas - now) / 1000 / 60 / 60 / 24); //248

• 시각 + 시간, 시각 - 시간

now.setTime(now.getTime() + (100*24*60*60*1000));
now.setTime(now.getTime() - (100*24*60*60*1000));
console.log(now.toLocaleDateString()); //2023. 7. 30.