Array whereusage : [{name : "William", age : 24}, {name : "Bertrand", age : 47}].where({age : 24}); => return : [{name : "William", age : 24}]

where.js

var where = function(data, predicate) {
    var newArray = [];
    data.forEach(function(e) {
        var add = true;
        for (pred in predicate) {
            if (predicate[pred] != e[pred]) {
                add = false;
                break;
            }
        }
        if (add)
            newArray.push(e);
    });
    return newArray;
};