Array.prototype.toMap

Array.prototype.toMap.js

/**
 * @param {Function} kvpFn - The function used to create the mapping. Return either the value to be used as key and the entire item will be set as the value, or return a key/value pair in the format [key, value] to specify both explicitely.
 * @returns {Map}
 */
Array.prototype.toMap = function (kvpFn){
    const input = this.map(kvpFn);
    if(!input.every(p => Array.isArray(p) && p.length === 2) {
        throw new TypeError('kvpFn must return a two element array tuple');
    }
    return new Map(input);
}


Array.prototype.toMap2 = function (keySelector, valueSelector = p=>p){
    return new Map(this.map(item => [keySelector(item), valueSelector(item)]));
}

neWay;