jquery find a string in an array with spaces on it

It appears you are using jQuery.

You could make a normalised copy of your Array with trimmed members.

arr = $.map(arr, $.trim);

(thanks Meouw and Felix.)

You can try using the grep function.

jQuery.grep(arr, function(n, i){
    if (jQuery.trim(n) == 'John') $("span:eq(0)").text(i);
    return false;
});

Your array has " John", but you're checking for "John". These are obviously different strings. This works for me:

<style>
  div { color:blue; }
  span { color:red; }
</style>

<div>"John" found at <span></span></div>
<div>4 found at <span></span></div>
<div>"Karl" not found, so <span></span></div>
<script>var arr = [ 4, "  Pete", 8, "  John" ];

$("span:eq(0)").text(jQuery.inArray("  John", arr));
$("span:eq(1)").text(jQuery.inArray(4, arr));
$("span:eq(2)").text(jQuery.inArray("Karl", arr));

</script>

Or are you wanting to do some sort of fuzzy matching that ignores spaces?

Use a trimmed copy if you want to ignore spaces. Make sure to only trim strings, else your lookup of 4 will fail:

var arr = [ 4, "  Pete", 8, "  John" ];
var trimmedArr = jQuery.map(arr, function(item)
{
    return typeof item == "string" ? jQuery.trim(item) : item;
});

$("span:eq(0)").text(jQuery.inArray("John", trimmedArr));
$("span:eq(1)").text(jQuery.inArray(4, trimmedArr));
$("span:eq(2)").text(jQuery.inArray("Karl", trimmedArr));

This method works (jsFiddle).

try not using jQuery, instead iterate through the array manually and use a RegExp. Replace jQuery.inArray("John", arr) with inArray("John", arr), and put the following function in your script:

function inArray(string, arr){
    var re = RegExp(string, "g");
    for(var i in arr){
        if(arr[i].search(re) != -1){
            return i;
        }
    }
}