JSFiddle - React, Tailwind, and code Playground

by Khalil Zhang

JavaScript

document.write('!! undefined: ' + !! undefined + '<br/>');
document.write('!! null:      ' + !! null + '<br/>');
document.write('!! true:      ' + !! true + '<br/>');
document.write('!! false:     ' + !! false + '<br/>');
document.write('!! NaN:       ' + !! NaN + '<br/>');
document.write("!! '':        " + !! '' + '<br/>');
document.write("!! '   ':     " + !! '   ' + '<br/>');
document.write('!! {}:        ' + !! {} + '<br/>');
document.write(' !! []:       ' + !! [] + '<br/>');
document.write(' !! function(){}: ' + !!
function() {} + '<br/>');