Function toggleButton

1-exercise-solutions/lesson-10/10g.js:2–14

(selector)

// The word "toggle" means turn on/off.
function toggleButton(selector) {
  const button = document.querySelector(selector);
  if (!button.classList.contains('is-toggled')) {

    // Before turning this button ON, check if there's
    // already a button that's turned ON and turn it OFF.
    turnOffPreviousButton();

    button.classList.add('is-toggled');
  } else {
    button.classList.remove('is-toggled');
  }
}

function turnOffPreviousButton() {
  const previousButton = document.querySelector('.is-toggled');