String validators
These are the most abused validators — precision matters.
String — Equal / Not Equal
Used for
Exact text matching.
How it works
- Direct string comparison
What it will find
- Exact matches
What it will not find
- Case variations
- Extra whitespace
- Synonyms
String — Contains / Not contains
Used for
Substring checks.
How it works
- Searches for text occurrence
What it will find
- Partial matches
What it will not find
- Word boundaries
- Regex patterns
- Semantic meaning
String — Part of / Not part of
Used for
Reverse containment (“value is part of X”).
How it works
- Checks if value is contained within a larger string
What it will find
- Embedded values
What it will not find
- Independent tokens
- Pattern-based matches
String — Not empty / Empty
Used for
Explicit emptiness checks.
How it works
- Tests for empty string
What it will find
""
What it will not find
null- Whitespace-only values (unless trimmed earlier)
String — Matches
Used for
Pattern-based validation.
How it works
- Applies regex to the string
What it will find
- Complex structured formats
- Naming conventions
- Codes
What it will not find
- Numeric logic
- Semantic correctness
- Values outside string context
Final rule
Validators do not make data correct. They only confirm whether data fits an expectation you already defined.
If you don’t know what question they are answering, the validator choice will always be wrong.