正则表达式“NOT”存在模式

Question

我有一个正则表达式，它匹配不以“DEF”开头的单词。

现在我想将其修改为以下三种情况：

1. 不以“DEF”结尾
2. 不包含“DEF”
3. 不等于“DEF”

我应该修改字符串模式？

Regex pattern Match word which does NOT start with word "DEF":  ^(?!DEF).*$
match word :  ADEFCCC
Does Not Match :   DEFXXX

Answer 1

Does not end with DEF:   ^.*(?<!DEF)$
Does not contain DEF:    ^((?!DEF).)*$
Does not equal DEF:      ^(?!DEF$).*$