The iswalnum() is a built-in function in C++ STL which checks if the given wide character is an alphanumeric character 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
- Digits: 0 to 9
Parameter: The function accepts a single mandatory parameter ch which specifies the wide character which we have to check that if it is alphanumeric or not.
Return Value: The function returns two values as shown below.
- If the ch is an alphanumeric character, then a non-zero value is returned.
- If it is not then 0 is returned.
Below programs illustrates the above function.
? is not alphanumeric g is alphanumeric
3 is alphanumeric & is not alphanumeric
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