How to verify a password to have at least one uppercase, lowercase and number in c?

如何验证密码至少有一个大写字母，小写字母和数字的C ？

youdao

Using the lowercase letter in general should be avoided, because it is easily mistaken for the number 1.

一般情况下，我们应该避免使用小写字母，因为它很容易被误当作数字1。

youdao

And s is this lowercase notation l that the spectroscopists use in place of the l number.

而s这个小写字母,被光谱学家用来代替数字。

麻省理工公开课 - 固态化学导论课程节选

You'll need a password of 7 to 12 characters, one uppercase, one lowercase, one number and, preferably, one character like an exclamation point or ampersand.

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