js-exercises/ejer10/10.js

function main() {
  var numAst = document.getElementById('numeroDeAsteriscos').value;
  for (let a = 0; a < numAst; a++) {
    for (let i = 0; i < numAst; i++) {
      document.writeln(`*`);
    }
    document.writeln(`<br>`)
  }
}