javascript 字符转换为ascii码，ascii码转换为字符

<script>
str="A";
code = str.charCodeAt();
str2 = String.fromCharCode(code);
str3 = String.fromCharCode(0x60+26);

document.write(code+\'<br />\');
document.write(str2+\'<br />\');
document.write(str3);
</script>