C/String/String Case

Change string case using its pointer

<source lang="cpp">

1. include <ctype.h>
2. include <stdio.h>

int main(void) {

 char str[80], *p;
 printf("Enter a string: ");
 gets(str);
 p = str;
 while( *p ) {
   *p = toupper(*p);
   p++;
 }
 printf("%s\n", str); /* uppercase string */
 p = str; /* reset p */
 while( *p ) {
   *p = tolower(*p);
   p++;
 }
 printf("%s\n", str); /* lowercase string */
 return 0;

}

      </source>

Convert string to upper case and lower case

<source lang="cpp">

1. include <ctype.h>
2. include <stdio.h>

int main(void) {

 char str[80];
 int i;
 printf("Enter a string: ");
 gets(str);
 for( i = 0; str[ i ]; i++)
   str[ i ] = toupper( str[ i ] );
 printf("%s\n", str); /* uppercase string */
 for(i = 0; str[ i ]; i++)
   str[i] = tolower(str[ i ]);
 printf("%s\n", str); /* lowercase string */
 return 0;

}

      </source>