JSFiddle - React, Tailwind, and code Playground

by ravan

HTML

<div id="r"></div>

CSS

#r { text-align: center }

JavaScript

function piramide(max) {
    var r = '';
    
    for (i = 0; i <= max; i++) {
        for (j = 1; j < i; j++) {
            r += j + ' ';
        }    
        for (j = i; j >= 1; j--) {
            r += j + ' ';
        }
        r += '<br />';
    }
    return r;
}

r = document.getElementById('r');
r.innerHTML = piramide(prompt('Máximo?'));