Character case-sensitive Conversion Function in C ++

Character case-sensitive Conversion Function in C ++

First, Judge

In lower case:

If (islower (str [I])

Converts lowercase letters into uppercase letters. The function is toupper.
Str [I] = toupper (str [I]);
Else

If it is a capital letter. The function to change to lowercase letters is: tolower
Str [I] = tolower (str [I]);

 

Check if the upper-case letter is isupper.

The lower-case letter is islower.

Upper case -------> lower case: tolower

Lower case --------> upper case: toupper

 

 

 

Example

Code:

# Include
# Include
# Include
# Define MAXN 21
Using namespace std;
Char str [MAXN];
Int main ()
{
Cin> str;
For (int I = 0; I <strlen (str); I ++)
{
If (islower (str [I])
Str [I] = toupper (str [I]);
Else if (isupper (str [I])
Str [I] = tolower (str [I]);
}
Cout < Return 0;
}