正则表达式需求：匹配含red不含ball的行及反向匹配规则

Got it, let's break down your regex needs with line-specific patterns tailored exactly to what you're asking for:

1. Match lines containing "red" but NOT "ball" (order doesn't matter) #

Use this regex to capture any full line that has "red" anywhere, but never includes "ball":

^(?=.*red)(?!.*ball).*$

Quick breakdown: #

• ^ anchors the match to the start of the line
• (?=.*red): Positive lookahead that checks if "red" exists anywhere in the line (.*/ covers any characters before it)
• (?!.*ball): Negative lookahead that guarantees "ball" does NOT show up anywhere in the line
• .*$ matches all remaining characters from the current spot to the end of the line

Which of your examples match? #

I have a red cup
This cup that I have is red

These lines have "red" and no trace of "ball" — they’ll get captured perfectly.

2. Match lines containing BOTH "red" and "ball" (order doesn't matter) #

This is the reverse rule, grabbing lines that include both terms no matter which comes first:

^(?=.*red)(?=.*ball).*$

Quick breakdown: #

• ^ start of line anchor
• (?=.*red): Makes sure "red" is present in the line
• (?=.*ball): Makes sure "ball" is also present in the line
• .*$ matches the entire line content

Which of your examples match? #

I have a red ball

This is the only line from your samples that includes both "red" and "ball" — it’s the one this regex will target.

内容的提问来源于stack exchange，提问作者Antonio