let str = "0123"; //要替换的字串
let letter= "ABCD"; //目的字符表
let num= "0123"; //原始字符表
for (let i = 0; i < letter.length; i++) {
str = eval("str.replace(/" + num.substr(i, 1) + "/g,'" + letter.substr(i, 1) + "')");
}
console.log(str);