Javascript Data Structure Hash Table with Quadratic Probing

function HashTable(size) {
    this.size = size;//w  ww  .j  av a  2s . c  om
    this.keys = this.initArray(size);
    this.values = this.initArray(size);
    this.limit = 0;
}

HashTable.prototype.put = function(key, value) {
    if (this.limit >= this.size) throw 'hash table is full'

    var hashedIndex = this.hash(key),
        squareIndex = 1;

    // quadratic probing
    while (this.keys[hashedIndex] != null) {
        hashedIndex += Math.pow(squareIndex, 2);

        hashedIndex
        squareIndex++;
    }

    this.keys[hashedIndex] = key;
    this.values[hashedIndex] = value;
    this.limit++;
}

HashTable.prototype.get = function(key) {
    var hashedIndex = this.hash(key),
        squareIndex = 1;

    while (this.keys[hashedIndex] != key) {
        hashedIndex += Math.pow(squareIndex, 2);

        hashedIndex = hashedIndex % this.size;
        squareIndex++;
    }

    return this.values[hashedIndex];
}

HashTable.prototype.hash = function(key) {
    // Check if int
    if (!Number.isInteger(key)) throw 'must be int';
    return key % this.size;
}

HashTable.prototype.initArray = function(size) {
    var array = [];
    for (var i = 0; i < size; i++) {
        array.push(null);
    }
    return array;
}

var exampletable = new HashTable(13);
exampletable.put(7, "A");
console.log(exampletable.get(7));
exampletable.put(20, "B");
console.log(exampletable.get(20));