hashTable.js

// Seperate Chaining
class Hashtable {
    constructor(size = 53) {
        this.keyMap = new Array(size)
    }

    _hash(key) {
        let total = 0;
        let WEIRD_PRIME = 31;
        for (let i = 0; i < Math.min(key.length, 100); i++) {
            let char = key[i]
            let value = char.charCodeAt(0) - 96;
            total = (total * WEIRD_PRIME + value) % this.keyMap.length;
        }
        return total
    }

    set(key, value) {
        var hashedKey = this._hash(key)
        if (!this.keyMap[hashedKey]) {
            this.keyMap[hashedKey] = []
        }
        this.keyMap[hashedKey].push([key, value])
        return this.keyMap;
    }
    
    get(key) {
        var hashedKey = this._hash(key)
        if (this.keyMap[hashedKey]) {
            for (let i of this.keyMap[hashedKey]) {
                if (i[0] === key) return i[1]
            }
        } 
        return undefined;
    }

    keys() {
        const arr = [];
        for (let keys of this.keyMap) {
            if (keys) {
                for (let key of keys) {
                    if (!arr.includes(key[0])) {
                        arr.push(key[0]);
                    }
                }
            }
        }
        return arr;
    }

    values() {
        const arr = [];
        for (let keys of this.keyMap) {
            if (keys) {
                for (let key of keys) {
                    if (!arr.includes(key[1])) {
                        arr.push(key[1]);
                    }
                }
            }
        }
        return arr;
    }
}