Javascript Generate Array Of Hours In The Day Starting With Current Hour

Hi I'm trying to generate an array of every hour of the day. However, I want it to start with the current hour. For example, if the current time is 2:00 pm, the array should star

Solution 1:

Pretty straight-forward. See comments inline:

var result = [];                      // Results will go herevar nowHour = newDate().getHours();  // Get current hour of the day// Loop from current hour number to 23for(var i = nowHour; i < 24; i++){
  result.push(i + "00");  // Put loop counter into array with "00" next to it
}

console.log(result); // show results

Solution 2:

You can use fill and map of Array.Prototype Something like below.

Array(24-newDate().getHours()).fill().map((e,i)=>i+newDate().getHours());

var currHour=newDate().getHours();
console.log(Array(24-currHour).fill().map((e,i)=>i+currHour+"00"));

Solution 3:

It can be done reasonably efficiently in a single statement, including leading zeros on hours before 10:00, and generically using Array.from with an optional callback, e.g.

console.log(
  Array.from(Array(24-newDate().getHours()),(x,i)=>('0'+(23-i)).slice(-2)+'00').reverse()
);

Unfortunately it still creates 2 arrays, the first is an empty array of the required length that is then used to generate the second array with the required values, so not much of a performance hit.

If there was a forEvery method that didn't skip non-existant properties in the same way from doesn't, it could be one with just one Array (just like a for loop does).