CHAR to upper

Posted on 2004-10-08
Last Modified: 2010-04-01
I have tried to use strupr(char) and it worked on's c++, but once I compiled on Linux it didn't work. Is there another function to change a char[4] to all uppercase?
Question by:microcoop
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LVL 33

Accepted Solution

hongjun earned 125 total points
ID: 12264430
try this

#include <ctype.h>


for ( i=0; i<3; i++ )
    mychar[i] = toupper(mychar[i]);

LVL 33

Expert Comment

ID: 12264455
complete program here

#include <stdio.h>
#include <ctype.h>

int main()
    char mychar[4]={'a', 'b', 'c', 'd'};
    int i;

    for ( i=0; i<3; i++ )
        printf("%c ", mychar[i]);

    for ( i=0; i<3; i++ )
        mychar[i] = toupper(mychar[i]);
    for ( i=0; i<3; i++ )
        printf("%c ", mychar[i]);

LVL 10

Expert Comment

ID: 12264487
This would work anywhere

#include <iostream>

using namespace std;

int main( int argc, char *argv[] ) {

    char    s[5] = "abcd" ;
    for ( int i = 0; i < 4 ; i ++ ) {
        s[i] = s[i] - 32 ;
    cout << s ;
    system ( "PAUSE" ) ;
    return 0 ;


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