is an option for string manipulation and searching functions that specifies whether lowercase and uppercase letters should be treated as equivalent.
IgnoreCase
is an option for string manipulation and searching functions that specifies whether lowercase and uppercase letters should be treated as equivalent.
Details
- With the default setting IgnoreCase->False , lowercase and uppercase letters are treated as totally different.
- With the setting IgnoreCase->True , lowercase and uppercase letters are treated as equivalent.
- IgnoreCase is an option for many string, file, and symbol name functions.
- IgnoreCase in no way affects the parsing of Wolfram Language expressions.
Examples
open all close allBasic Examples (1)
With IgnoreCase->True , lowercase and uppercase letters are treated as equivalent:
Use IgnoreCase->False to treat lowercase and uppercase letters as distinct letters:
Scope (5)
IgnoreCase is set to False by default:
Find positions of successive identical characters independent of case:
This replaces all occurrences regardless of case:
Determine alphabetic order independent of case:
With IgnoreCase->True , WordFrequency will count all case variations to compute the frequency:
Tech Notes
Related Guides
Related Workflows
- Analyze the Text on a Webpage
History
Introduced in 1991 (2.0)
Text
Wolfram Research (1991), IgnoreCase, Wolfram Language function, https://reference.wolfram.com/language/ref/IgnoreCase.html.
CMS
Wolfram Language. 1991. "IgnoreCase." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/IgnoreCase.html.
APA
Wolfram Language. (1991). IgnoreCase. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/IgnoreCase.html
BibTeX
@misc{reference.wolfram_2025_ignorecase, author="Wolfram Research", title="{IgnoreCase}", year="1991", howpublished="\url{https://reference.wolfram.com/language/ref/IgnoreCase.html}", note=[Accessed: 04-January-2026]}
BibLaTeX
@online{reference.wolfram_2025_ignorecase, organization={Wolfram Research}, title={IgnoreCase}, year={1991}, url={https://reference.wolfram.com/language/ref/IgnoreCase.html}, note=[Accessed: 04-January-2026]}