Question

I have associated array:

[
    {
        "attr_1":"value 1_1",
        "attr_2":"value 2_1",
        "attr_3":"value 3_1"
    },
    {
        "attr_1":"value 2_1",
        "attr_2":"value 2_2",
        "attr_3":"value 2_3"
    },
    {
        "attr_1":"value 1_1",
        "attr_2":"value 3_2",
        "attr_3":"value 3_3"
    }
]

And I need to get full object, by requesting ‘value 1_1’, for example. After request I want to see Object 1 and Object 3. I suppose that i need hash, but i don’t know how 🙁

How can I do this correctly?

Answer 1

This is the perfect case for Array.filter!

yourArray.filter( function(elem) {
  // Loop attr_1, attr_2, attr_3
  for ( var i in elem ) {
    if ( elem[i] == 'value 1_1' ) {
      return true;
    }
  }
});

Array.filter is native in all the browser but not on IE8 and below.
In that case you have to include this polyfill

/**
 * Copyright (c) Mozilla Foundation http://www.mozilla.org/
 * This code is available under the terms of the MIT License
 */
if (!Array.prototype.filter) {
    Array.prototype.filter = function(fun /*, thisp*/) {
        var len = this.length >>> 0;
        if (typeof fun != "function") {
            throw new TypeError();
        }

        var res = [];
        var thisp = arguments[1];
        for (var i = 0; i < len; i++) {
            if (i in this) {
                var val = this[i]; // in case fun mutates this
                if (fun.call(thisp, val, i, this)) {
                    res.push(val);
                }
            }
        }

        return res;
    };
}

More info:
http://www.diveintojavascript.com/core-javascript-reference/the-array-object/array-filter