变量名应由26个大小写字母(A..Z,a..z),10个数字(0..9),和_(下划线)组成。

Names should be formed from the 26 upper and lower case letters (A .. Z, a .. z), the 10 digits (0 .. 9), and _ (underbar).

youdao

用户名是由字母数字和下划线空格组成。

The username is letter or number and underline space .

youdao

用户名是由字母数字和下划线空格组成。

The username is letter or number and underline space .

youdao