JSFiddle - React, Tailwind, and code Playground

by Arjun Singh

HTML

<pre id=0>

JavaScript

f=n=>{a=[];w=" ";u="_";t=`/\\${u.repeat(n*3+2)}/\\
`;for(i=0;i<n+1;i++){c=i==n?u:w;a.push(`${w.repeat(i)}\\ \\${c.repeat((n+1-i*2)+n+(n-1))}/ /
`)};return [t,...a,`${w.repeat(i)}\\${u.repeat(n+2)}/`].join``}

document.getElementById("0").innerHTML = f(+prompt("Enter a number"));