_tolower

Remonter à Ctype.h - Index

Header File

ctype.h

Category

Conversion Routines

Prototype

int _tolower(int ch);

Description

_tolower is a macro that does the same conversion as tolower, except that it should be used only when ch is known to be uppercase (AZ).

To use _tolower, you must include ctype.h.

Return Value

_tolower returns the converted value of ch if it is uppercase; otherwise, the result is undefined.

Example

 #include <string.h>
 #include <stdio.h>
 #include <ctype.h>
 int main(void)
 {
    int length, i;
    char *string = "THIS IS A STRING.";
    length = strlen(string);
    for (i = 0; i < length; i++) {
        if ((string[i] >= 'A') && (string[i] <= 'Z')){
           string[i] = _tolower(string[i]);
        }
    }
    printf("%s\n",string);
    return 0;
 }

Portability

POSIX	Win32	ANSI C	ANSI C++
	+