数字转大小写字母

        var id=1;
        var id2=1;
        console.log(id);//1
        id=String.fromCharCode(64 + parseInt(id));
        console.log(id);//A
        console.log(id2);//1
        id2=String.fromCharCode(96 + parseInt(id2));
        console.log(id2);//a