Boolean Functions in C++

Boolean function returns only true or false. If the condition is correct it returns true else it returns false. Boolean functions are used to find the correctness of the condition.

C++ uses a built-in library(cctype) that contains boolean functions like isdigit(), islower(), isupper() etc. These functions work only on characters

#include<iostream>
#include<cctype>
using namespace std;
int main(){
	char k;
	cout<<"Enter a character : ";
	cin>>k;
        cout<<"It is a ";
	if(isdigit(k))cout<<"Digit";
	else if(islower(k))cout<<"Lower Case";
	else if(isupper(k))cout<<"Upper Case";
	else cout<<"Other Character";
	return 0;
}

Other functions present are

• isdigit(k)
• islower(k)
• isupper(k)
• isspace(k)
• iscntrl(k)
• ispunct(k)

Try all of these functions.