Function allows to find entity in array/object by key and value. @param `keyObj` – key and value, i.e. {id:10}.

findEntity.js

Object.prototype.findEntity = function(keyObj) {
    var arr = this, p, key, val, ret;
    for (p in keyObj) {
        if (keyObj.hasOwnProperty(p)) {
            key = p;
            val = keyObj[p];
        }
    }
    for (p in arr) {
        if (p == key) {
            if (arr[p] == val) {
                return arr;
            }
        } else if (arr[p] instanceof Object) {
            if (arr.hasOwnProperty(p)) {
                ret = findEntity(arr[p], keyObj);
                if (ret) {
                    return ret;
                }
            }
        }
    }
    return false;
};