Programming-Idioms.org

document.write("Hello World!");

console.log('Hello World');

for (let i = 0; i < 10; i++) {
  console.log("Hello");
}

let count = 0;
while (count < 10) {
  count++; 
  console.log('Hello');
};

[...Array(10)].forEach(() => console.log('Hello'))

console.log( 'Hello\n'.repeat(10) )

var bli = function() { 
	console.log('Hello World!!!');
}

function bli() { 
	console.log('Hello World!!!');
}

let dog = 'Poodle';
const dogAlert = () => alert(dog);

const greet = who => console.log(`Hi ${who}!`)

function square(x) { 
	return x * x;
}

const square = (x) => x * x;

const square = n => n**2

const square = (number) => Math.pow(number, 2);

var p = { x: 1.122, y: 7.45 };

const point = { x: 1, y: 2 };

items.forEach((x) => {
    doSomething(x);
});

for (x of items) {
	doSomething(x);
}

items.forEach(doSomething)

for (var i = 0; i<items.length; i++) {
  var x = items[i];
  doSomething(x);
}

items.map(doSomething)

items.forEach((val, idx) => {
  console.log("index=" + idx + ", value=" + val);
});

for (var i in items) {
   console.log("index=" + i + ", value=" + items[i]);
}

const x = {one: 1, two:2}

const x = new Map();
x.set("one", 1);
x.set("two", 2);

const x = new Map([["one",1],["two",2]]);

class Node {
  constructor (data) {
    this.data = data
    this.left = null
    this.right = null
  }
}

for (var i = x.length - 1; i > 0; i--) {
    var j = Math.floor(Math.random() * (i + 1));
    var temp = x[j];
    x[j] = x[i];
    x[i] = temp;
}

x[Math.floor(Math.random() * x.length)]

x[~~(Math.random() * x.length)];

return list.indexOf(x) !== -1;

return list.includes(x);

Object.entries(mymap).forEach(([key, value]) => {
	console.log('key:', key, 'value:', value);
});

for (const key in mymap) {
    console.log('key:', key, 'value:', mymap[key]);
}

a + (b-a) * Math.random();

a + Math.random() * (b - a)

function pick(a, b) {
    return a + Math.floor(Math.random() * (b - a + 1));
}

function dfs(bt) {
	if (bt === undefined) return;
	dfs(bt.left);
	f(bt);
	dfs(bt.right);
}

class Node {
  constructor (value, children = []) {
    this.value = value
    this.children = children
  }
}

function DFS(f, root) {
	f(root)
	if (root.children) {
		root.children.forEach(child => DFS(f, child))
	}
}

x = x.reverse();

function search(m, x) {
    for (var i = 0; i < m.length; i++) {
        for (var j = 0; j < m[i].length; j++) {
            if (m[i][j] == x) {
                return [i, j];
            }
        }
    }
    return false;
}

var tmp = a;
a = b;
b = tmp;

[a, b] = [b, a];

let i = parseInt(s, 10)

const i = Number(s);

const i = +s

num.toFixed(2)

s = "ネコ";

{
  // in file worker.js
  onmessage = ({data}) => {
    console.log (`Hello, ${data}`)
  }
}
{
  // in file main.js
  const worker = new Worker ('worker.js')
  worker.postMessage ('Alan')
}

if (isMainThread) {
  const worker = new Worker(new URL(import.meta.url));
  worker.postMessage('Alan');
} else {
  parentPort.once('message', (message) => {
    console.log(`Hello, ${message}`);
  });
}

var x = [];
for (var i = 0; i < m; i++) {
  x[i] = [];
}

const x = new Array(m).fill(new Array(n).fill(Math.random()));

const x = new Array(m).fill(
  new Array(n).fill(
    new Array(p).fill(Math.random())
  )
)

items.sort(function(a,b) {
  return compareFieldP(a.p, b.p);
});

let new_list = items.filter(function(val,idx,ary) { return idx != i });

items.splice(i,1);

for (let i = 1; i <= 1000; i++) setTimeout(() => f(i), 0);

function f(i) {
   return i<2 ? 1 : i * f(i-1);
}

const f = i => i === 0 ? 1 : i * f(i-1)

function exp(x, n) {
   if (n===0) return 1;
   if (n===1) return x;
   return n%2 ? x * exp(x*x, (n-1)/2)
              : exp(x*x, n/2);
}

const exp = Math.pow;

let x = f(x)

let x = new Set();

function compose(f,g){
    return function(x){
        return g(f(x));
    };
}

function compose(f,g){
    return function(x){
        return g(f(x));
    };
}

const compose = f => g => x => g(f(x));

function curry (fn, scope) {
   
    scope = scope || window;
    
    // omit curry function first arguments fn and scope
    var args = Array.prototype.slice.call(arguments, 2);
    
    return function() {
	var trueArgs = args.concat(Array.prototype.slice.call(arguments, 0));
        fn.apply(scope, trueArgs);
    };
}

const curry = (fn, ...initialArgs) => (...args) => fn(...initialArgs, ...args);

const add = (a, b) => a + b;

const add5 = curry(add, 5);

const result = add5(1) // 6

let t = s.substring(i, j);

let t = s.slice(i, j);

var ok = s.indexOf(word) !== -1;

var ok = s.includes(word);

var t = s.split("").reverse().join("");

OUTER:
for (var i in a) {
   for (var j in b) {
      if (a[i] === b[j]) {
         continue OUTER;
      }
   }
   console.log(a[i] + " not in the list");
}

OUTER:
for (var i in m) {
   for (var j in m[i]) {
      if (m[i][j] < 0) {
         console.log("Negative value found: "+m[i][j]);
         break OUTER;
      }
   }
}

s.splice(i, 0, x);

setTimeout(function(){
	// Instructions after delay
},5000);

const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));

await sleep(5000);

await new Promise(r => setTimeout(r, 5000));

let t = s.substring(0,5);

var t = s.slice(-5);

let s = "This is a very long string which needs \n" +
        "to wrap across multiple lines because \n" +
        "otherwise my code is unreadable.";

let s = "This is a very long string which needs \
to wrap across multiple lines because \
otherwise my code is unreadable.";

let s = `This is a very long string which needs 
to wrap across multiple lines because 
otherwise my code is unreadable.`;

let chunks = s.split(/ +/);

while (true) {
	// to infinity
}

for(;;) {
	console.log('Oops')
}

k in m

m.hasOwnProperty(k)

_m.has(_k)

Object.values(m).includes(v)

[...m.values()].includes(v)

y = x.join(", ");

var s = x.reduce((a, b) => a + b, 0);

var s = x.reduce((a, b) => a + b)

var s = i.toString();

var s = i + "";

{
  // in file worker.js
  onmessage = f
}
{
  // in file main.js
  for (let i = 0; i < 1000; i++) {
    new Worker ('worker.js')
      .postMessage (i)
  }
}

const tasks = [];
for (let i = 0; i < 1000; i++) {
  tasks.push(f(i));
}

await Promise.all(tasks);
console.log("Finished");

y = x.filter(p);

fs.readFile(f, (err, lines) => {
    if (err) {
        // Handle error...
    }

    // Work with `lines` here.
}

console.error(util.format("%d is negative", x));

console.error(x, "is negative");

console.error(`${x} is negative`);

const x = process.argv[2]

var d = Date.now();

var d = new Date();

let i = x.indexOf(y);

var x2 = x.replace(new RegExp(y, 'g'), z);

const x2 = x.replaceAll(y, z);

let x = 3n ** 247n;

const s = Math.round (x * 1000) / 10 + '%'

const percentFormatter = new Intl.NumberFormat('en-US', {
  style: 'percent',
  maximumSignificantDigits: 3
});

const s = percentFormatter.format(x);

let z = x**n

const fac = x => x ? x * fac (x - 1) : x + 1
const binom = (n, k) => fac (n) / fac (k) / fac (n - k >= 0 ? n - k : NaN)

let x = new Buffer (Math.ceil (n / 8))

seed (s)

Math.random ()

console.log(process.argv.slice(2).join(" "));

class Parent {
    constructor(str) {}
    fact(new_class, str) {
        if (new_class.prototype instanceof Parent) {
            return new new_class(str)
        }
    }
}

class Child extends Parent {}

const gcd = (a, b) => b === 0 ? a : gcd (b, a % b)

const gcd = (a, b) => b === 0 ? a : gcd (b, a % b)
let x = (a * b) / gcd(a, b)

let s = x.toString(2);

var x = math.complex(-2, 3);
x = math.multiply(x, math.i);

do {
   something();
} while (c);

let y = x + .0

let y = BigInt (x | 0)

var y = Math.round(x);

let n = 0 // the number of occurences
let acc = s
let i
while ((i = acc.indexOf (t)) + 1) {
  n++
  acc = acc.slice (i + 1)
}

const r = /htt+p/

const c = i.toString(2).replace(/[^1]/g, '').length

function addingWillOverflow(x, y) {
  return x > 0 && y > 0 && x > Number.MAX_SAFE_INTEGER - y
}

process.exit()

let buf = new Buffer (1e6)

throw new Error ('x is invalid')

const Foo = function Counter () {
  let n = 0
  Object.defineProperty (this, 'value', {get: () => n++})
}
{
  const counter = new Foo ()
  counter.value // 0
  counter.value // 1
}

class Foo {
  #x = 123;
  get x() {
    return this.#x;
  }
}

const x = JSON.parse(fs.readFileSync('./data.json'));

const x = require('./data.json');

fs.writeFileSync('data.json', JSON.stringify(x));

function control(f){
	f();
}

console.log(typeof x);

console.log (x == null ? x + '' : x.constructor.name);

let x = read(path).length

var b = s.startsWith(prefix);

var b = (s.lastIndexOf(prefix, 0) === 0);

var b = s.endsWith(suffix);

new Date (ts * 1000)

let x = d.toISOString().slice(0, 10)

items.sort(c);

$.get(u, function(data){
  s = data;
});

var xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange = function() { 
	if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
		s = xmlHttp.responseText;
}
xmlHttp.open("GET", u, true);
xmlHttp.send(null);

fetch(u)
  .then(res => res.text())
  .then(text => s = text)

const res = await fetch(u)
s = await res.text()

var s = process.argv0;

let dir = process.cwd ()

const dir = path.resolve();

const dir = __dirname;

if (typeof x !== 'undefined') {
    console.log(x);
}

try {
	console.log(x);
} catch (e) {
	if (!e instanceof ReferenceError) {
		throw e;
	}
}

const blank = s == null || s.trim() === ''

exec(`${x} a b`);

[...mymap.entries()].sort().map(([_, x]) => console.log(x))

Object.entries(mymap)
  .sort((a, b) => a[1] - b[1])
  .forEach(([key, value]) => {
    console.log('key:', key, 'value:', value);
  });

const b = JSON.stringify(x) === JSON.stringify(y);

const arrayDeepEqual = (a, b) => a.length === b.length && a.every((x, i) => deepEqual(x, b[i]))

const deepEqual = (a, b) =>
  Array.isArray(a) && Array.isArray(b)
    ? arrayDeepEqual(a, b)
    : typeof a == 'object' && a && typeof b == 'object' && b
    ? arrayDeepEqual(Object.entries(a), Object.entries(b))
    : Number.isNaN(a) && Number.isNaN(b) || a === b

const b = deepEqual(x, y)

const b = isDeepStrictEqual(x, y)

const b = _.isEqual(x, y);

let b = d1 < d2

var regex = RegExp(w, 'g');
var s2 = s1.replace(regex, '');

const s2 = s1.split(w).join('')

var n = x.length;

var y = new Set(x);

x = [...new Set(x)];

x = Array.from(new Set(x));

const seen = new Set();
x = x.filter( v => {
  if(seen.has(v))
    return false;
  seen.add(v);
  return true;
});

const {createInterface} = require('readline')

const rl = createInterface ({
  input: process.stdin,
  output: process.stdout
})

rl.question('Input an integer: ', response => {
  let n = parseInt (response)
  // stuff to be done with n goes here

  rl.close()
})

const spades = 0
const hearts = 1
const diamonds = 2
const clubs = 3

console.assert(_isConsistent);

function binarySearch(a, x, i = 0) {
  if (a.length === 0) return -1
  const half = (a.length / 2) | 0
  return (a[half] === x) ?
    i + half :
    (a[half] > x) ?
    binarySearch(a.slice(0, half), x, i) :
    binarySearch(a.slice(half + 1), x, half + i + 1)
}

console.time('foo');
foo();
console.timeEnd('foo');

const foo = () => ({string: 'string', bool: true})

const foo = () => ['string', true];

const foo = new Function(await readFile('foobody.txt'));

c1 ? f1 : c2 ? f2 : f3

switch (true) {
  case c1:
    f1();
    break;
  case c2:
    f2();
    break;
  case c3:
    f3();
    break;
}

if (c1) {
  f1();
} else if (c2) {
  f2();
} else if (c3) {
  f3();
}

function clock(f) {
  var start = new Date().getTime();
  f();
  var end = new Date().getTime();
  return end - start;
}

function clock(f) {
  var start = performance.now();
  f();
  var end = performance.now();
  return end - start;
}

var lowerS = s.toLowerCase();
var lowerWord = word.toLowerCase();
var ok = lowerS.indexOf(lowerWord) !== -1;

const items = [a, b, c];

const items = new Array(a, b, c);

const idx = items.indexOf(x)
if (idx !== -1) items.splice(idx, 1)

const newlist = items.filter(y => x !== y)

var b = /^[0-9]+$/.test(s);

const tempFile = tempy.file()

const resultOfCallback = tempy.file.task(tempFile => {
 // do something with tempFile
})

const tempDir = await Deno.makeTempDir();

m.delete(k)

for (let item of items1) console.log(item)
for (let item of items2) console.log(item)

items1.concat(items2).forEach(console.log)

const s = x.toString(16)

const shorter = _items1.length > _items2.length ? _items2 : _items1;
const longer = _items1.length <= _items2.length ? _items2 : _items1;
shorter.map((m, i) => {
  console.log(m);
  console.log(longer[i]);
});

const iterator1 = items1[Symbol.iterator]()
const iterator2 = items2[Symbol.iterator]()

let result1 = iterator1.next()
let result2 = iterator2.next()

while(!(result1.done && result2.done)) {
  if (!result1.done) {
    console.log(result1.value)
    result1 = iterator1.next()
  }
  if (!result2.done) {
    console.log(result2.value)
    result2 = iterator2.next()
  }
}

const b = fs.existsSync(fp);

let b = true;
try {
	await access(fp);
} catch {
	b = false;
}

try {
	Deno.statSync(fp)
} catch(_e) {console.error("File does not exist.")}

console.log(Date(), msg);

console.error(Date(), msg);

let f = +s

const t = [...s].filter(c => c.charCodeAt(0) <= 0x7f).join('')

const t = s.replace(/[^\x00-\x7f]/gu, '')

process.stdin.on('data', processLine)

function processLine (line) {
  const string = line + ''
  console.log(string)
}

const ints = await new Promise(resolve => {
  let string = ''
  process.stdin
    .on('data', data => string += data.toString())
    .on('close', () => resolve(string.split('\n').map(line => Number.parseInt(line))))
})

const slashscrape = p => (
  p.slice (-1) === '/' ?
    p.slice (0, -1) :
    p
)

p = p.endsWith(path.sep) ? p.slice(0, -path.sep.length) : p

let s = c

let t = s + i;

let t = `${s}${i}`

var c = "#";
for(var i = 0; i<3; i++) {
  var sub1 = c1.substring(1+2*i, 3+2*i);
  var sub2 = c2.substring(1+2*i, 3+2*i);
  var v1 = parseInt(sub1, 16);
  var v2 = parseInt(sub2, 16);
  var v = Math.floor((v1 + v2) / 2);
  var sub = v.toString(16).toUpperCase();
  var padsub = ('0'+sub).slice(-2);
  c += padsub;
}

c = "#" + (() => {
  const [p1, p2] = [c1, c2].map((color) => parseInt(color.slice(1), 16)),
    a = [];

  for (let i = 0; i <= 2; i += 1) {
    a.push(Math.floor(((p1 >> (i * 8) & 0xff) + (p2 >> (i * 8) & 0xff)) / 2));
  }

  return a.reverse().map((num) => num.toString(16).padStart(2, "0")).join("");
})();

try {
  fs.unlinkSync(filepath);
} catch (err) {
  console.error(err);
}

await unlink(filepath)

Deno.remove(filepath, { recursive: true }).catch((err) => console.error(err));

let s = i.toString();
if(i<100)
  s = ('00'+i).slice(-3);

const planet = 'Earth'

const idx = x.map((item, i) => i);
while (y.length < k) {
  const i = parseInt(Math.random() * idx.length, 10);
  y.push(x[[idx[i]]]);
  idx.splice(i, 1);
}

const is64Bit = os.arch() === 'x64' || process.env.hasOwnProperty('PROCESSOR_ARCHITEW6432');
is64Bit ? _f64() : _f32();

elements = elements.map(x => x * c)

const args = process.argv.slice(2)
if (args.includes('b')) bat()
else if (args.includes('f')) fox()

for (let index = 0; index < list.length; index = index + 2) {
  console.log(list[index], list[index + 1])
}

const x = items[items.length - 1];

const x = items.at(-1);

var ab = a.concat(b);

let t = s.startsWith(p) ? s.substring(p.length) : s;

const t = s.endsWith(w) ? s.slice(0, -w.length) : s

const n = s.length;

const n = [...s].length;

const n = mymap.size

s.push(x);

s = [...s, x];

m.set(k, v);

m[k] = v;

new Intl.NumberFormat().format(1000);

fetch(u, {
        method: "POST",
	body: JSON.stringify(data)
})

const s = Buffer.from(a).toString('hex')

const s = a.map(n => n.toString(16).padStart(2, '0')).join('')

s
  .split('')
  .map((el, ix, arr) => ix % 2 ? null : el + arr[ix + 1])
  .filter(el => el !== null)
  .map(x => parseInt(x, 16))

const pointInRect = ({x1, y1, x2, y2}, {x, y}) => (
  (x > x1 && x < x2) && (y > y1 && y < y2)
)

const center = ({x1, y1, x2, y2}) => ({x: (x1 + x2) / 2, y: (y1 + y2) / 2})

class Point {
  constructor (x, y) {
    this.x = x
    this.y = y
  }
}
const center = ({x1, y1, x2, y2}) => new Point ((x1 + x2) / 2, (y1 + y2) / 2)

const x = fs.readdirSync(d)

c=console.log
q=decodeURIComponent('%22')
l=[
"c=console.log",
"q=decodeURIComponent('%22')",
"l=[",
"]",
"for(i=0;i<3;i++)c(l[i])",
"for(i=0;i<7;i++)c(q+l[i]+q+',')",
"for(i=3;i<7;i++)c(l[i])",
]
for(i=0;i<3;i++)c(l[i])
for(i=0;i<7;i++)c(q+l[i]+q+',')
for(i=3;i<7;i++)c(l[i])

fetch(u, {
        method: "PUT",
	body: JSON.stringify(data)
})

var nextDate = new Date(new Date().getTime() + 24 * 60 * 60 * 1000);
var day = nextDate.getDate()
var month = nextDate.getMonth() + 1
var year = nextDate.getFullYear()
var t = `${day}/${month}/${year}`;

var tomorrow = new Date();
tomorrow.setDate(tomorrow.getDate() + 1);

var now = new Date()
var year = now.getFullYear()
var month = now.getMonth()
var day = now.getDate()

var tomorrow = new Date(0)
tomorrow.setFullYear(year, month, day + 1)
tomorrow.setHours(0, 0, 0, 0)

var shortDateFormat = Intl.DateTimeFormat(undefined, { dateStyle: "short" })
var t = shortDateFormat.format(tomorrow)

let id = setTimeout(f, 30000, 42);

process.exit()

y = x.filter(e => P(e)).map(e => T(e))

if(a.some(item => item > x)){
	f()
}

const a = [[1, 2, 3], [4, 5, 6]]
const m = a[0].length
const b = Array.from({ length: m }, (_, n) => a.map(row => row[n]))

/**
 * @param {Array<Array>} arry
 *
 * @return {Array<Array>}
 */
function foo(arry) {
  let len = 0;
  let sum = 0;

  arry.forEach(function(base, i) {
    len += base.length;

    base.forEach(function(a, j) {
      sum += a * (i + 1) * (j + 1);
    });
  });

  console.log('Array size:', arry.length, ',', len);

  return sum;
}

foo(arry2d);

fs.readFileSync(path).split("\n")

process.exit(x);

var h = Math.sqrt(x*x + y*y);

const h = Math.hypot(x, y);

const n = Math.hypot(...data)

var n = Math.hypot.apply(null, data)

s = data.reduce((a, c) => a + c ** 2, 0)

function frexp(a) {
    exponent = ( Math.floor(Math.log(a, 2)) + 1 )
    mantissa = ( a * Math.pow(2, -a) )

    return [ mantissa, exponent ]
}

const foo = process.env["FOO"] || "none";

const foo = process.env.FOO ?? 'none'

switch (str) {
  case "foo":
    foo();
    break;
  case "bar":
    bar();
    break;
  case "baz":
    baz();
    break;
  case "barfl":
    barfl();
    break;
}

a.forEach((aa, i) => a[i] = e * (aa + b[i] * c[i] + Math.cos(d[i])))

const { version } = process;
console.log(version);

await mkdir(path);

s = s.padEnd(m, c);

s = s.padStart(m, c);

const c = [...new Set(a)].filter(e => b.includes(e));

let t = s.replace(/\s+/g, ' ');

let t = [2.5, "hello", -1];

t = s.replace(/[^\d]/gm,"");

let i = items.indexOf(x);

const found = items.some(condition);

if (!found) doSomethingElse();

items.unshift(x);

items = [x, ...items];

function f(x) {
	console.log(x ? `Present: ${x}` : 'Not present');
}

items.pop();

let y = x.slice();

copyFileSync(src, dst);

const verbose = process.argv.includes('-v');
console.log('verbose is', verbose);

let s = btoa(data);

var data = atob(s)

const c = a ^ b;

const c = Uint8Array.from(a, (v, i) => v ^ b[i])

const matches = s.match(/\b\d{3}\b/);
const x = matches ? matches[0] : '';

for (const e of x) {
	f(e);
}

let v = x.values();
let result = v.next();
while (!result.done) {
  f(result.value);
  result = v.next();
}

x.forEach(f);

console.log(a);

console.table(a);

console.log(m);

console.table(m);

console.log(x);

const c = new Set(items).size;

for (const [key, value] of x.entries()) {
	if (!p(value)) x.splice(key, 1);
}

x = x.filter((e) => p(e));

const [a, b, c] = [42, "hello", 5.0];

// Objects
const values = Object.values(m);

// Maps
const values = [...m.values()];

const x = values[~~(Math.random() * values.length)]

const i = parseInt(s, 2)

const x = condition() ? 'a' : 'b';

console.trace()

x = x.map(e => e === 'foo' ? 'bar' : e);

console.log(x);

for (let i = 5; i >= 0; i--) {
  console.log(i)
}

[...items].reverse().forEach((item, index) => 
console.log(Math.abs(index -= items.length), item));

let b = a.map(Number)

var parts = s.split(/[-_,]/)

let items = [];

const d = new Date();

let hr = d.getHours();
let min = d.getMinutes();
let sec = d.getSeconds();

if ( hr.toString().length === 1 ) {
  hr = '0' + hr;
}

if ( min.toString().length === 1 ) {
  min = '0' + min;
}

if ( sec.toString().length === 1 ) {
  sec = '0' + sec;
}

const x = '' + hr + ':' + min + ':' + sec;

let i = 42
i.toString(2)
  .split('')
  .reduce((parity, bit) => parity ^ bit, 0)

const s = v.repeat(n)

function foo(x) {
  console.log(typeof x == 'string' ? x : 'Nothing.')
}

foo('Hello, world!')
foo(42)

for (let i = 1; i <= 100; i++) {
    let out = "";
    if (!(i % 3)) out += "Fizz";
    if (!(i % 5)) out += "Buzz";
    if (!out) out = i;
    console.log(out);
}

let t = s.replace(/\s/g,'');

x.add(e);

let letters = new Set(["a","b","c"]);
letters.delete("b");
console.log([...letters].join(', '));

const parts = s.split(sep);

const a = new Array(n).fill(0);

for (const [i, c] of [...s].entries()) {
	console.log(`Char ${i} is ${c}`);
}

let b = x.has(e);

const s = a + b;

const s = [1, 2, 3];
s.push(x);
const y = s.pop();

// This is a comment

let s = `Our sun has ${x} planets`;

const data = new TextEncoder().encode(s);

let s = n.toString(b);

let y = structuredClone(x);

let c = x.filter(p).length

const s = ((n) => {
    const alphanum = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    let s = "";
    for (let i = 0; i < n; i += 1) {
        s += alphanum[~~(Math.random() * alphanum.length)];
    }
    return s;
})(n);

let t = s.toLowerCase();

let t = s.toUpperCase();

v = m.get(k);

m.clear()

let c = {...a, ...b}