RegEx for a string to NOT contain two different strings

Question

Ok you gurus out there who know Regex! How do you use reg ex to search a string to make sure it doesn't contain either of two different strings. Example: Say i want to make sure "FileNTile" doesnt contain File or Tile Thanks cnorr

Accepted Answer

```
^((?!File|Tile).)*$
```

This is unlikely to be a good idea though. Almost every programming environment will have a clearer and more efficient approach with string matching. (eg Python: `if 'File' not in s and 'Tile' not in s`)

Also not all regex implementations have lookahead. eg. it's not reliable in JavaScript. And there may be issues with newlines depending on mode (multiline, dotall flags).

RegEx for a string to NOT contain two different strings

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