0706-design-hashmap.js

var MyHashMap = function () {
    this.map = new Map();
};

/**
 * @param {number} key
 * @param {number} value
 * @return {void}
 */
MyHashMap.prototype.put = function (key, value) {
    this.map.set(key, value);
};

/**
 * @param {number} key
 * @return {number}
 */
MyHashMap.prototype.get = function (key) {
    const val = this.map.get(key);
    return val !== undefined ? val : -1;
};

/**
 * @param {number} key
 * @return {void}
 */
MyHashMap.prototype.remove = function (key) {
    this.map.delete(key);
};

/**
 * Your MyHashMap object will be instantiated and called as such:
 * var obj = new MyHashMap()
 * obj.put(key,value)
 * var param_2 = obj.get(key)
 * obj.remove(key)
 */