time conversion hackerrank solution stack overflow js
function get24hTime(str){
str = String(str).toLowerCase().replace(/\s/g, '');
var has_am = str.indexOf('am') >= 0;
var has_pm = str.indexOf('pm') >= 0;
// first strip off the am/pm, leave it either hour or hour:minute
str = str.replace('am', '').replace('pm', '');
// if hour, convert to hour:00
if (str.indexOf(':') < 0) str = str + ':00';
// now it's hour:minute
// we add am/pm back if striped out before
if (has_am) str += ' am';
if (has_pm) str += ' pm';
// now its either hour:minute, or hour:minute am/pm
// put it in a date object, it will convert to 24 hours format for us
var d = new Date("1/1/2011 " + str);
// make hours and minutes double digits
var doubleDigits = function(n){
return (parseInt(n) < 10) ? "0" + n : String(n);
};
return doubleDigits(d.getHours()) + ':' + doubleDigits(d.getMinutes());
}
console.log(get24hTime('6')); // 06:00
console.log(get24hTime('6am')); // 06:00
console.log(get24hTime('6pm')); // 18:00
console.log(get24hTime('6:11pm')); // 18:11
console.log(get24hTime('6:11')); // 06:11
console.log(get24hTime('18')); // 18:00
console.log(get24hTime('18:11')); // 18:11