console.log("A0azAZ09".charCodeAt(2));//ASCII码
console.log(String.fromCharCode(65));
console.log("0aA".charCodeAt(0));
console.log(String.fromCharCode(48));
console.log("A0azAZ09".charCodeAt(2));//ASCII码
console.log(String.fromCharCode(65));
console.log("0aA".charCodeAt(0));
console.log(String.fromCharCode(48));