HashTable.js

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) {
        let index = this._hash(key);
        if (!this.keyMap[index]) {
            this.keyMap[index] = []
        }
        this.keyMap[index].push([key, value]);
    }

    get(key) {
        let index = this._hash(key);
        if (this.keyMap[index]) {
            for (let i = 0; i < this.keyMap[index].length; i++) {
                if (this.keyMap[index][i][0] === key) {
                    return this.keyMap[index][i][1];
                }
            }
        }
        return undefined;
    }

    keys() {
        let keysArr = [];
        for (let i = 0; i < this.keyMap.length; i++) {
            if (this.keyMap[i]) {
                for (let j = 0; j < this.keyMap[i].length; j++) {
                    if (!keysArr.includes(this.keyMap[i][j][0])) {
                        keysArr.push(this.keyMap[i][j][0]);
                    }
                }
            }
        }
        return keysArr;
    }

    values() {
        let valuesArr = [];
        for (let i = 0; i < this.keyMap.length; i++) {
            if (this.keyMap[i]) {
                for (let j = 0; j < this.keyMap[i].length; j++) {
                    if (!valuesArr.includes(this.keyMap[i][j][1])) {
                        valuesArr.push(this.keyMap[i][j][1]);
                    }
                }
            }
        }
        return valuesArr;
    }
}

let ht = new HashTable(17);
ht.set("maroon","#800000");
ht.set("yellow","#FFFF00");
ht.set("olive","#808000");
ht.set("salmon","#FA8072");
ht.set("lightcoral","#F08080");
ht.set("mediumvioletred","#C71585");
ht.set("plum","#DDA0DD");
ht.set("purple","#DDA0DD");
ht.set("violet","#DDA0DD");

console.log(JSON.stringify(ht));
ht.keys().forEach(function(key){
  console.log(key +'=='+ht.get(key));
})