A regex designed to capture the ejection fraction from clinical notes

写一个正则表达式判断一个字符串是否是ip地址 规则：一个ip地址由4个数字组成，每个数字之间用.连接。每个数字的大小是0-255 例如：255.189.10.37 正确 256.189.89.9 错误

check if a gives string is a domain 检查一个给定的字符串是不是域名

lawbyte

https://www.php-fig.org/psr/psr-16/ Key - A string of at least one character that uniquely identifies a cached item. Implementing libraries MUST support keys consisting of the characters A-Z, a-z, 0-9, _, and . in any order in UTF-8 encoding and a length of up to 64 characters. Implementing librarie...