Relational and logical operators

Relational operators are used to compare values with each other. They return a logical result: true or false. Values that are linked with relational operators are called elementary statements in propositional logic.
A typical example of a Boolean logical operator is the and operation: It always returns true if all operands are also true.

Code Example

#include <iostream>
using namespace std;

int main() {
	int a = 0, i = 20, b = 8;
	while (a != b && i >= a+b) {
		cout << a << " is equal " << b << endl;
		a++;
	}
	cout << a << " is unequal " << b << endl;
}

Output

0 is equal 8
1 is equal 8
2 is equal 8
3 is equal 8
4 is equal 8
5 is equal 8
6 is equal 8
7 is equal 8
8 is unequal 8

Code Explanation

1. Inside the main() function, three variables are declared and initialized:
   • a is an int variable initialized with the value 0.
   • i is an int variable initialized with the value 20.
   • b is an int variable initialized with the value 8.
2. The while loop is used to execute a block of code repeatedly as long as a certain condition is true.
3. The condition (a != b && i >= a+b) is checked before each iteration of the loop. The loop will continue as long as a is not equal to b and the value of i is greater than or equal to the sum of a and b.
4. If the condition is true, the code block inside the loop is executed. The code outputs the string a is equal b, where a and b are the values of the variables, and then increments the value of a by 1 using the a++ statement.
5. Once the condition (a != b && i >= a+b) becomes false, the loop terminates, and the program continues with the next line of code.
6. The line cout << a << " is unequal " << b << endl; outputs the string a is unequal b, where a and b are the final values of the variables after the loop.