SpeechSynthesisEvent: charLength プロパティ

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2018.

charLength は SpeechSynthesisEvent 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。

値

整数です。

例

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

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