How can I check JavaScript arrays for empty strings?

Question

I need to check if array contains at least one empty elements. If any of the one element is empty then it will return false.

Example:

var my_arr = new Array(); 
my_arr[0] = ""; 
my_arr[1] = " hi ";
my_arr[2] = "";

The 0th and 2nd array elements are "empty".

Answer 1

You can check by looping through the array with a simple for, like this:

function NoneEmpty(arr) {
  for(var i=0; i<arr.length; i++) {
    if(arr[i] === "") return false;
  }
  return true;
}

You can give it a try here, the reason we're not using .indexOf() here is lack of support in IE, otherwise it'd be even simpler like this:

function NoneEmpty(arr) {
  return arr.indexOf("") === -1;
}

But alas, IE doesn't support this function on arrays, at least not yet.

Answer 2

You could do a simple help method for this:

function hasEmptyValues(ary) {
    var l = ary.length,
        i = 0;

    for (i = 0; i < l; i += 1) {
        if (!ary[i]) {
            return false;
        }
    }

    return true;
}

//check for empty
var isEmpty = hasEmptyValues(myArray);

EDIT: This checks for false, undefined, NaN, null, "" and 0.

EDIT2: Misread the true/false expectation.

..fredrik

Answer 3

You have to check in through loop.

function checkArray(my_arr){
   for(var i=0;i<my_arr.length;i++){
       if(my_arr[i] === "")   
          return false;
   }
   return true;
}

Answer 4

You can try jQuery.inArray() function:

return jQuery.inArray("", my_arr)

Answer 5

I see in your comments beneath the question that the code example you give is PHP, so I was wondering if you were actually going for the PHP one? In PHP it would be:

function hasEmpty($array)
{
  foreach($array as $bit)
  {
    if(empty($bit)) return true;
  }

  return false;
}

Otherwise if you actually did need JavaScript, I refer to Nick Craver's answer

Answer 6

function containsEmpty(a) {
    return [].concat(a).sort().reverse().pop() === "";
}
alert(containsEmpty(['1','','qwerty','100'])); // true
alert(containsEmpty(['1','2','qwerty','100'])); // false

Answer 7

Just do a len(my_arr[i]) == 0; inside a loop to check if string is empty or not.