1const ok = "a";
2console.log(ok.codePointAt(0).toString(16)); // 61: occupies < 1 byte
3
4const notOK = "✓"
5console.log(notOK.codePointAt(0).toString(16)); // 2713: occupies > 1 byte
6
7console.log(btoa(ok)); // YQ==
8console.log(btoa(notOK)); // error