Result マウスドラッグした文字数を数えます。JSはバニラです 使う機会があるかは分かりません jsfunction biR() { document.addEventListener("mousedown", rOS); document.addEventListener("mouseup", rOS); document.addEventListener("onkeyup", rOS); document.addEventListener("onkeydown", rOS); document.addEventListener("onkeydown", rOS); document.onselectionchange = function() { rOS(); }; } function rOS() { var cout, rts, rt; c = window.getSelect
![マウスで選択した文字数を数える](https://cdn-ak-scissors.b.st-hatena.com/image/square/b6b1c87ada2ad66409793e3653c810e333009609/height=288;version=1;width=512/http%3A%2F%2Fkachibito.net%2Fwp-content%2Fuploads%2F2019%2F12%2Fsite-icon.png)