function
<cctype>
tolower
Convert uppercase letter to lowercase
Converts c to its lowercase equivalent if c is an uppercase letter and has a lowercase equivalent. If no such conversion is possible, the value returned is c unchanged.
Notice that what is considered a letter may depend on the locale being used; In the default "C" locale, an uppercase letter is any of: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z, which translate respectively to: a b c d e f g h i j k l m n o p q r s t u v w x y z.
In other locales, if an uppercase character has more than one correspondent lowercase character, this function always returns the same character for the same value of c.
In C++, a locale-specific template version of this function (tolower) exists in header <locale>.
Parameters
- c
- Character to be converted, casted to an int, or EOF.
Return Value
The lowercase equivalent to c, if such value exists, or c (unchanged) otherwise.
The value is returned as an int value that can be implicitly casted to char.
Example
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/* tolower example */
#include <stdio.h>
#include <ctype.h>
int main ()
{
int i=0;
char str[]="Test String.\n";
char c;
while (str[i])
{
c=str[i];
putchar (tolower(c));
i++;
}
return 0;
}
| |
Output:
See also
- toupper
- Convert lowercase letter to uppercase (function
)
- isupper
- Check if character is uppercase letter (function
)
- islower
- Check if character is lowercase letter (function
)
- isalpha
- Check if character is alphabetic (function
)