Looping through array and output as pairs (divider for each second element)

Question

I have an array with anonymous elements. Elements are added to the array via php, like so:

$playlist = array();

while (databaseloop) {
  $playlist[] = $a_ti         


        

Answer 1

Destructive, but clean:

while (arr.length) {
  const Title  = arr.shift();
  const Length = arr.shift();

  // Do work.
}

Answer 2

Using Array.prototype.reduce():

let pairs = playlist.reduce((list, _, index, source) => {
    if (index % 2 === 0) {
        list.push(source.slice(index, index + 2));
    }
    return list;
}, []);

This gives you a 2-dimensional array pairs to work with.

Answer 3

var arr = ["Hello.mp3", "00:00:14", "Byebye.mp3", "00:00:30", "Whatsup.mp3", "00:00:07", "Goodnight.mp3", "00:00:19"];

var group = [];
for (var x = 0; x < arr.length; x += 2) {
    var track = arr[x],
        length = arr[x + 1];
    group.push({
       track: track,
       length: length
    })
}