# towlower

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< c‎ | string‎ | wide

Defined in header `<wctype.h>` |  |
wint_t towlower( wint_t wc ); |  | (since C95)

Converts the given wide character to lowercase, if possible.

### Parameters

wc | - | wide character to be converted

### Return value

Lowercase version of `wc` or unmodified `wc` if no lowercase version is listed in the current C locale.

### Notes

Only 1:1 character mapping can be performed by this function, e.g. the Greek uppercase letter 'Σ' has two lowercase forms, depending on the position in a word: 'σ' and 'ς'. A call to `towlower` cannot be used to obtain the correct lowercase form in this case.

ISO 30112 specifies which pairs of Unicode characters are included in this mapping.

### Example

Run this code

    #include <stdio.h>
    #include <wchar.h>
    #include <wctype.h>
    #include <locale.h>

    int main(void)
    {
        wchar_t wc = L'\u0190'; // Latin capital open E ('Ɛ')
        printf("in the default locale, towlower(%#x) = %#x\n", wc, towlower(wc));
        setlocale(LC_ALL, "en_US.utf8");
        printf("in Unicode locale, towlower(%#x) = %#x\n", wc, towlower(wc));
    }

Output:

    in the default locale, towlower(0x190) = 0x190
    in Unicode locale, towlower(0x190) = 0x25b

### References

- C11 standard (ISO/IEC 9899:2011):

  - 7.30.3.1.1 The towlower function (p: 453)

- C99 standard (ISO/IEC 9899:1999):

  - 7.25.3.1.1 The towlower function (p: 399)

### See also

towupper (C95) | converts a wide character to uppercase (function)
tolower | converts a character to lowercase (function)

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