js 字符串与16进制互转代码

将字符串转成16进制：

function stringToHex(str) {
  let hex = "";
  for(let i=0; i<str.length; i++) {
    let charCode = str.charCodeAt(i).toString(16);
    hex += charCode.length < 2 ? "0" + charCode : charCode;
  }
  return hex;
}

将16进制转成字符串：

function hexToString(hex) {
  let str = "";
  for(let i=0; i<hex.length; i+=2) {
    let charCode = parseInt(hex.substr(i, 2), 16);
    str += String.fromCharCode(charCode);
  }
  return str;
}

使用示例：

let str = "hello world";
let hex = stringToHex(str);
console.log(hex); // 68656c6c6f20776f726c64
console.log(hexToString(hex)); // hello world