MediaQueryList.addListener()

The deprecated addListener() method of the MediaQueryList interface adds a listener to the MediaQueryListener that will run a custom callback function in response to the media query status changing.

In older browsers MediaQueryList did not yet inherit from EventTarget, so this method was provided as an alias of EventTarget.addEventListener(). Use addEventListener() instead of addListener() if it is available in the browsers you need to support.

MediaQueryList.addListener(func)

func

A function or function reference representing the callback function you want to run when the media query status changes.

Void.

var paragraph = document.querySelector('p');
var mediaQueryList = window.matchMedia('(max-width: 600px)');

function screenTest(e) {
  if (e.matches) {
    /* the viewport is 600 pixels wide or less */
    paragraph.textContent = 'This is a narrow screen — 600px wide or less.';
    document.body.style.backgroundColor = 'pink';
  } else {
    /* the viewport is more than than 600 pixels wide */
    paragraph.textContent = 'This is a wide screen — more than 600px wide.';
    document.body.style.backgroundColor = 'aquamarine';
  }
}

mediaQueryList.addListener(screenTest);

• Media queries
• Using media queries from code
• window.matchMedia()
• MediaQueryList
• MediaQueryListEvent