php ctype函数及其模拟函数ctype_alnum ctype_alpha ctype_cntrl ctype_digit ctype_lower ctype_print ctype_punct
Ctype函数是PHP内置的字符串体测函数。主要有以下几种ctype_alnum — Check for alphanumeric character(s)检测是否是只包含[A-Za-z0-9]ctype_alpha — Check for alphabetic character(s)检测是否是只包含[A-Za-z]ctype_cntrl — Check for co
