Pluck an object that contains a key and optional value

getby.js

// Pluck an object that contains a key and optional value
function getBy(enumerable, findProperty, findValue){
    return jQuery.map(enumerable, function(el){
        if (typeof el[findProperty] !== 'undefined'){
            if (typeof findValue === 'undefined' ||
                el[findProperty] === findValue){
                return el;
            }
        }
    });
}