array_search Recursive in javascript

Question

function array_searchRecursive( $needle, $haystack, $strict=false, $path=array() )
{
    if( !is_array($haystack) ) {
        return false;
    }

    foreach( $haystack as $key => $val ) {

        if( is_array($val) && $subPath = array_searchRecursive($needle, $val, $strict, $path) ) {
            $path = array_merge($path, array($key), $subPath);

            return $path;
        } else if( (!$strict && $val == $needle) || ($strict && $val === $needle) ) {

            $path[] = $key;
            return $path;
        }
    }
    return false;
}

Do any body suggest me the same funcitonality, that can be implemented in javascript. reference http://www.php.net/manual/en/function.array-search.php#68424

Answer 1

This might give you a start. Not thoroughly tested or highly optimized, and assumes use of jQuery (shouldn't be a big problem to replace the jQuery utilty functions with other implementations).

function searchArrayRecursive(needle, haystack, strict) {

    function constructPath(needle, haystack, path, strict) {
        if (!$.isArray(haystack)) {
            return false;
        }
        var index;
        for (index = 0; index < haystack.length; index++) {
            var value = haystack[index];
            var currentPath = $.merge([], path);
            currentPath.push(index);

            if ((strict && value === needle) || (!strict && value == needle)) {
                return currentPath;
            }
            if ($.isArray(value)) {

                var foundPath = constructPath(needle, value, currentPath, strict);
                if (foundPath) {
                    return foundPath;
                }
            }
        }

        return false;
    }


    return constructPath(needle, haystack, [], strict);
}

http://jsfiddle.net/b8TxJ/2/

Answer 2

Indeed underscore (or probably better performing: lodash) is your man. JavaScript is for a huge part a functional language and in the latest spec contains most features that underscore provides. For browser-compat underscore is still adviced.

The best underscore feature in your situation is:

var haystack = [
  {a: 1}, [{b: 2}, {c: 3}, [{d: 4}, {e: 5}, [{f: 6}, {g: 7}] ] ]
],
needle = 4;

//Search
var result = _(haystack).chain() //chain so we can keep underscoring
  .flatten() //flatten the array
  .find(function(o) { //find the first element that matches our search function
    return _(o).chain() //chain so we can keep underscoring
      .values() //get all object values as an array
      .contains(needle) //see if any of our values contains the needle
      .value(); //get out of the chain
  })
  .value(); //get out of the chain

//In short:
var result = _(haystack).chain().flatten().find(function(o) { return _(o).chain().values().contains(needle).value(); }).value();

Of course you will have to fine-tune this and implement your $strict and whatsoever.

Answer 3

If you are open to using libraries, I think Underscore.js has functionality that will get you what you're looking for, using possibly _.find(), _.pluck(), or _.pick(). There are plenty of other methods that can help with this.

• http://underscorejs.org/#find
• http://underscorejs.org/#pluck
• http://underscorejs.org/#pick

If you want to do it in core JS, have a peek under the covers of Underscore source code, which has FANTASTIC annotations / documentation:

http://underscorejs.org/docs/underscore.html