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C++ cctype tolower() Function

❮ cctype Functions


Example

Convert a character to lowercase:

char upper = 'A';
char lower = tolower(upper);

cout << upper << " in lowercase is " << lower;

Try it Yourself »


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Definition and Usage

The tolower() function returns the lowercase version of a character. If the character is not an uppercase letter, like '5' or '!', it is returned without any change.

The function returns an int, so store the result in a char, like in the example. If you print the result directly, cout << tolower('A') prints 97 (the ASCII value of a), not a.

The tolower function is defined in the <cctype> header file.

Tip: See how tolower() is used in How To Count Vowels in a String.


Syntax

int tolower(int c);

Parameter Values

Parameter Description
c Required. The character to convert.

Technical Details

Returns: An int with the lowercase version of the character. If the character is not an uppercase letter, it is returned unchanged.

Related Pages

Read more about strings in our Strings Tutorial.


❮ cctype Functions

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