[문제풀이]hackerrank - Time Conversion
function timeConversion(s) {
const arr = s.split(':')
if (arr[2].substring(2, 4) == 'PM' && arr[0] < 12) {
arr[0] = Number(arr[0]) + 12 === 24 ? '00' : Number(arr[0]) + 12;
}
if (arr[0] == 12 && arr[2].substring(2, 4) == 'AM') {
arr[0] = '00';
}
arr[2] = arr[2].substring(0, 2);
return arr.join(':');
}