const mil = 1000000;

const arr = Array(mil);

console.time('⏲️');

for (let i = 0; i < mil; i++) {} // 1.6ms

for (const v of arr) {

} // 11.7ms

arr.forEach(v => v); // 2.1ms

for (let i = mil; i > 0; i--) {} // 1.5ms

console.timeEnd('⏲️');

const equine = { unicorn: '🦄', horse: '🐴', zebra: '🦓' };

for (const key in equine) {

// Filters out properties inherited from prototype

if (equine.hasOwnProperty(key)) {

console.log(equine[key]);

}

}

// Unwrap the the Values

for (const val of Object.values(equine)) {

console.log(val);

}

// Create a Map

const equine = new Map(Object.entries(equine));

for (const v of equine.values()) {

console.log(v);

}

const equine = [

['unicorn', '🦄'],

['horse', '🐴'],

['zebra', '🦓'],

];

// 😒 Meh Code

for (const arr of equine) {

const type = arr[0];

const face = arr[1];

console.log(`${type} looks like ${face}`);

}

// 🤯 Destructured Code

for (const [type, face] of equine) {

console.log(`${type} looks like ${face}`);

}

///////////////

arr[Symbol.iterator] = function () {

let i = 0;

let arr = this;

return {

next: function () {

if (i >= arr.length) {

return { done: true };

} else {

const value = arr[i] + '🙉';

i++;

return { value, done: false };

}

},

};

};

////////////////////////////////

const faces = ['😀', '😍', '🤤', '🤯', '💩', '🤠', '🥳'];

// Transform values

const withIndex = faces.map((v, i) => `face ${i} is ${v}`);

// Test at least one value meets a condition

const isPoopy = faces.some(v => v === '💩');

// false

// Test all values meet a condition

const isEmoji = faces.every(v => v > 'ÿ');

// true

// Filter out values

const withoutPoo = faces.filter(v => v !== '💩');

// Reduce values to a single value

const pooCount = faces.reduce((acc, cur) => {

return acc + (cur === '💩' ? 1 : 0);

}, 0);

console.log(pooCount);

// Sort the values

const sorted = faces.sort((a, b) => a < b);