Input checked change body background colour using JS

Question

I have an input checkbox. I want to change all the body CSS of the HTML (white body-background and black text when unchecked, and black body-background and white text when checked).

HTML:

  <input id="nightmode" type="checkbox">Activate night mode

Answer 1

You can try to check for a change in the checkbox, then set the background color and text color accordingly.

document.getElementById("nightmode").addEventListener("change", function() {
  if (document.getElementById("nightmode").checked == true) {
    document.documentElement.setAttribute("style", "background-color: black;");
    document.getElementsByTagName("body")[0].setAttribute("style", "color: white;");

  } else {
    document.documentElement.setAttribute("style", "background-color: white;");
    document.getElementsByTagName("body")[0].setAttribute("style", "color: black;");
  }
});

<input id="nightmode" type="checkbox">Activate night mode
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