recreating Array.splice from scratch

splicey.js

Array.prototype.splicey = function(position, number, values) {
    if (!position) return this

    var newNumber = number || this.length
    var newThis = []

    for (var i = position; i <= position + newNumber; i++) {
        if (values) {
            if (Array.isArray(values)) {
                this[i].push(values)
            } else {
                var prevPosition = i

                for (var value in values) {
                    this[prevPosition].push(value)
                    prevPosition++
                }
            }
        } else {
            
        }
    }

    return newThis
}