The iswalpha() is a built-in function in C++ STL which checks if the given wide character is an alphabet or not. It is defined within the cwctype header file of C++.
The following characters are alphanumeric:
- Uppercase letters: A to Z
- Lowercase letters: a to z
Parameter: The function accepts a single mandatory parameter ch which specifies the wide character which we have to check that if it is an alphabet or not.
Return Value: The function returns two values:
- If the ch is an alphanumeric character, then a non-zero value is returned.
- If it is not an alphanumeric character, then 0 is returned.
Below programs illustrate the above function.
Q is an alphabet g is an alphabet
w is an alphabet 2 is not an alphabet
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