Calculate Days Left To A Specific Date With Javascript

I was trying to calculate the days left until a specific date. I know that there are a million different approaches and tutorials about it, but I wanted to write a code by myself.

Solution 1:

When you parse num to set date[x], you need to reset num to ''.

...
else {
    date[x] = parseInt(num, 10);
    x++;
    num = '';
}

You might consider using String.split() to separate your input at the periods.

Solution 2:

My Solution is:

functionisNumeric(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

var daysLeft = function(input) {
    var num = '';
    var date = [];
    var x = 0;
    for (i = 0; i < input.length; i++) {
        if (!isNaN(input.charAt(i)) && isNumeric(input.charAt(i))) {
            num += input.charAt(i);
        }
        else {
            date[x] = parseInt(num, 10);
            x++;
            num = '';
        }
    }
    date[x] = parseInt(num, 10);

    var inputDate = newDate(date[2], date[1], date[0]);
    var today = newDate();
    var timeDiff = Math.abs(inputDate.getTime() - today.getTime());
    returnMath.ceil(timeDiff / (1000*3600*24));
};

But a better would be:

functionparseDate(input) {
  var parts = input.split('-');
  // new Date(year, month [, day [, hours[, minutes[, seconds[, ms]]]]])returnnewDate(parts[0], parts[1]-1, parts[2]); // Note: months are 0-based
}

var daysLeft = function(input) {    
    var inputDate = parseDate(input);
    var today = newDate();
    var timeDiff = Math.abs(inputDate.getTime() - today.getTime());
    returnMath.ceil(timeDiff / (1000*3600*24));
};

Solution 3:

You should use something like this:

var daysLeft = function(input) {
    var num = '';
    var date = [];
    var x = 0;
    for (i = 0; i < input.length; i++) {
        if (!isNaN(input.charAt(i))) {
            num += input.charAt(i);
        }
        else {
            date[x] = parseInt(num, 10);
            x++;
            num='';
        }
    }
    date[x] = parseInt(num, 10);
    var inputDate = newDate(date[2], date[1], date[0]);
    var today = newDate();
    var timeDiff = Math.abs(inputDate.getTime() - today.getTime());
    returnMath.ceil(timeDiff / (1000*3600*24));
};
daysLeft("11.12.2014");