JSFiddle - React, Tailwind, and code Playground

by huuzoo

HTML

<p>（例：月が綺麗ですね。と夏目漱石がいいました。）</p>
<textarea rows="4" cols="40"  id="sentenceBox" onkeyup="sentenceCheck()"></textarea>
<p>文章数：<span id="countArea"></span></p>

JavaScript

function sentenceCheck() {
	var sentenceValue = document.getElementById("sentenceBox").value;
  var splitArray = sentenceValue.split('。')
  var sentenceLength = splitArray.length - 1;
  document.getElementById("countArea").innerHTML = sentenceLength;
}