SpeechSynthesisEvent: charLength プロパティ

charLengthSpeechSynthesisEvent インターフェイスの読み取り専用プロパティで、 charIndex の位置にある文字の後に発話される残りの文字数を返します。

音声エンジンが判断できない場合は 0 を返します。

整数です。

js
utterThis.onpause = (event) => {
  const char = event.utterance.text.charAt(event.charIndex);
  const charLeft = event.charLength;
  if (charLeft) {
    console.log(
      `Speech paused. There are still ${charLeft} characters to be spoken.`,
    );
  } else {
    console.log(
      "Speech paused. The underlying speech engine can't tell how many characters are left.",
    );
  }
};

仕様書

Specification
Web Speech API
# dom-speechsynthesisevent-charlength

ブラウザーの互換性

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
charLength

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support