strupr(): String Upper Case in C Programming

String handling function strupr() is used to convert all lower case letter in string to upper case i.e. strlwr(str) converts all lower case letter in string str to upper case.

strlwr() Syntax

strupr( string);

strlwr() Program

#include<stdio.h>
#include<string.h>

int main()
{
 char str[40];

 printf("Enter string:\n");
 gets(str);
 strupr(str);
 printf("String in uppercase is:");
 puts(str);
 
 return 0;
}

strlwr() Program Output

Enter string:
WeLcOmE To C 101. ↲
String in lowercase is:
WELCOME TO C 101.