MediaQueryList.matches - Web APIs 编辑

The matches read-only property of the MediaQueryList interface is a Boolean that returns true if the document currently matches the media query list, or false if not.

You can be notified when the value of matches changes by watching for the change event to be fired at the MediaQueryList.

Syntax

var matches = <varm>MediaQueryList.matches;

Value

A Boolean which is true if the document currently matches the media query list; otherwise, it's false.

Examples

This example detects viewport orientation changes by creating a media query using the orientation media feature:

function addMQListener(mq, callback) {
  if (mq.addEventListener) {
    mq.addEventListener("change", callback);
  } else {
    mq.addListener(callback);
  }
}

addMQListener(window.matchMedia("(orientation:landscape)"),
  event => {
    if (event.matches) {
      /* now in landscape orientation */
    } else {
      /* now in portrait orientation */
    }
  }
);

Specifications

Browser compatibility

BCD tables only load in the browser

See also

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