Unicodeの文字数をバイト単位で数える
UTF-8で数える場合
JavaScript
code:js
const utf8Blob = new Blob(value, {type: "text/plain;charset=utf-8"}); // value は文字列 const utf8Count = utf8Blob.size; // これで取れる。
document.getElementById("outputUtf8ByteLength").textContent = utf8Count;
// 後はおまけ
const utf8Buffer = await utf8Blob.arrayBuffer();
const uint8Array = new Uint8Array(utf8Buffer);
const strUtf8 = (utf8Count > 0) ? "+ Array.from(uint8Array).map((code)=> { return code.toString(16).padStart(2, "0"); }).join("','") + "'" : "[]";
document.getElementById("outputUtf8").textContent = strUtf8;