function isOnlyEnglishLetters(s) {
const pattern = /^[a-zA-Z]+$/;
return pattern.test(s);
}
const s1 = "NodeJS";
console.log(isOnlyEnglishLetters(s1));
const s2 = "NodeJSプログラミング";
console.log(isOnlyEnglishLetters(s2));
const s3 = "NodeJSv23.5.0";
console.log(isOnlyEnglishLetters(s3));
/*
run:
true
false
false
*/