new StringBuilder(hi).reverse().toString()

import { configureStore } from "@reduxjs/toolkit";
import { combineReducers } from "redux";
import profile from "./profile";
import auth from "./auth";
import alert from "./alert";

const reducer = combineReducers({
	profile,
	auth,
	alert,
});

const store = configureStore({ reducer });

export default store;

// `arr` is an array
const clone = arr => arr.slice(0);

// Or
const clone = arr => [...arr];

// Or
const clone = arr => Array.from(arr);

// Or
const clone = arr => arr.map(x => x);

// Or
const clone = arr => JSON.parse(JSON.stringify(arr));

// Or
const clone = arr => arr.concat([]);

//QM Helper by Leif Messinger
//Groups numbers by number of bits and shows their binary representations.
//To be used on x.com
const minterms = prompt("Enter your minterms separated by commas").split(",").map(x => parseInt(x.trim()));
const maxNumBits = minterms.reduce(function(a, b) {
	return Math.max(a, Math.log2(b));
});
const bitGroups = [];
for(let i = 0; i < maxNumBits; ++i){
	bitGroups.push([]);
}
for(const minterm of minterms){
	let outputString = (minterm+" ");
	//Count the bits
	let count = 0;
	for (var i = maxNumBits; i >= 0; --i) {
		if((minterm >> i) & 1){
			++count;
			outputString += "1";
		}else{
			outputString += "0";
		}
	}
	bitGroups[count].push(outputString);
}
document.body.textContent = "";
document.body.style.setProperty("white-space", "pre");
for(const group of bitGroups){
	for(const outputString of group){
		document.body.textContent += outputString + "\r\n";
	}
}

const head = arr => (arr && arr.length ? arr[0] : undefined);

head([1, 2, 3]); // 1
head([]); // undefined
head(null); // undefined
head(undefined); // undefined

// `date` is a `Date` object
const formatYmd = date => date.toISOString().slice(0, 10);

// Example
formatYmd(new Date());      // 2020-05-06