Document.queryCommandState() - Web APIs 编辑

Obsolete

This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

The queryCommandState() method will tell you if the current selection has a certain Document.execCommand() command applied.

Syntax

queryCommandState(String command)

Parameters

command is a command from Document.execCommand()

Return value

queryCommandState() can return a Boolean value or null if the state is unknown.

Example

HTML

<div contenteditable="true">Select a part of this text!</div>
<button onclick="makeBold();">Test the state of the 'bold' command</button>

JavaScript

function makeBold() {
  var state = document.queryCommandState("bold");
  switch (state) {
    case true:
      alert("The bold formatting will be removed from the selected text.");
      break;
    case false:
      alert("The selected text will be displayed in bold.");
      break;
    case null:
      alert("The state of the 'bold' command is indeterminable.");
      break;
  }
  document.execCommand('bold');
}

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• HTMLElement.contentEditable
• document.designMode
• Rich-Text Editing in Mozilla
• Browser bugs related to queryCommandState(): Scribe's "Browser Inconsistencies" documentation