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javascript - Trigger event based on specific inputs into a textarea

I'm trying to trigger a JS event when there are four consecutive linebreaks inside of a textarea.

The situation causing this would either be that a person presses the RETURN key four times, a person pastes text that contains four line breaks, or they delete some content (ie a paragraph) that results in four consecutive linebreaks.

Thanks

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by (71.8m points)

Try below solution:

document.getElementById("textArea").addEventListener("keyup", function(event) {
  var numberOfLineBreaks = (this.value.match(/
/g)||[]).length;
  if (numberOfLineBreaks === 4) {
    console.log("4 consecutive Lines!");
  }
});

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