In Javascript, how do I put single quotes around an array I just "joined"?

Question

[3, 4, 5]
['4', '1', 'abc123']


function combine_ids(ids){
    return ids.join(',');
};

No matter what type of list, I want my function to return a string with single quotes around the elements.

The function should return:

'3','4','5'

and

'4','1','abc123'

I want my resulting string to have single quotes in them!

Answer 1

Simple logic!

function combine_ids(ids) {
   return (ids.length ? "'" + ids.join("','") + "'" : "");
}

---

Example:

console.log(combine_ids([]));
console.log(combine_ids([3]));
console.log(combine_ids([3, 4, 'a']));

Example output:

(an empty string)
'3'
'3','4','a'

Answer 2

how do I put single quotes around an array I just “joined”?

Your approach seems to be unnecessarily complex. You better off:

1. Create intermediate array with all elements converted toString and quoted
2. join the intermediate array

---

[03:22:35.728] [3, 4, 5].map( function (element) { return "'" + String(element) + "'" } ).join(",")
[03:22:35.736] "'3','4','5'"
--
[03:22:58.925] ['4', '1', 'abc123'].map( function (element) { return "'" + String(element) + "'" } ).join(",")
[03:22:58.933] "'4','1','abc123'"

Note: map method required JS 1.6+, versions below are requiring you to iterate an array "manually":

function combine_ids( array ) {
  var tmp = [];
  for ( var i = 0; i < array.length; i++ ) {
    tmp[i] = "'" + String( array[i] ) + "'";
  }
  return tmp.join(",");
}