Question

Describe numerical, relational, and logical operators and give a few examples for each.

Answer 1

1) -------------Numerical operator----------------

Numerical Operators are the type of operators which take numerical values (either literals or variables) as their operands and return a single numerical value.

Operator	Description	Example
+	Adds operands	a+b=12
-	Subtracts second operand from the first	a-b=4
*	Multiplies both operands	a*b=32
/	Divides numerator by denominator.	a/b=2
%	Modulus Operator returns the remainder after an integer division.	a%b=0

Example:-

int main()
{
    int a = 25;
    int b = 8;
    printf("sum = %d", (a+b));
    printf("\ndifference = %d", (a-b));
    printf("\nproduct = %d", (a*b));
    printf("\nremainder = %d\n", (a%b));
    return 0;
}

output:

sum = 33
difference = 17
product = 200
remainder = 1

Now let's talk about '/'.

If we divide two integers, the result will be an integer.

5/2=2  (Not 2.5)

To get 2.5, at least one of the numerator or denominator must have a decimal(float) value.

5.0/2=2.5     or     5/2.0=2.5     or     5.0/2.0=2.5     but     5/2 = 2.

#include <stdio.h>
int main()
{
    int a ;
    int b ;
    a = 2 ;
    b = 9 ;
    printf ( "Value of b/a is : %d\n" , b/a ) ;
    return 0;
}

Value of b/a is : 4

#include <stdio.h>
int main()
{
    float a ;
    int b ;
    a = 2.0 ;
    b = 9 ;
    printf ( "Value of b/a is : %f\n" , b/a ) ;
    return 0;
}

Value of b/a is : 4.500000

As we saw, if 'b' and 'a' are both integers, then the result is 4 (not 4.5) but when one of them is float then the result is 4.500000 (a float).

2) -----------------------------------Relational operator-----------------------------------

Relational Operators check the relationship between two operands. If the relationship is true, it returns 1, if the relationship is false, it returns 0.

Operator	Description	Example
==	Equal to	(a == b) is false
!=	Not equal to	(a != b) is true
>	Greater than	(a > b) is true
<	Less than	(a < b) is false
>=	Greater than or equal to	(a >= b) is true
<=	Less than or equal to	(a <= b) is false

Example

#include <stdio.h>
int main()
{
    int a = 5, b = 6;
    printf("\n%d", a == b);
    printf("\n%d", a != b);
    printf("\n%d", a > b);
    printf("\n%d", a < b);
    printf("\n%d", a >= b);
    printf("\n%d", a <= b);
    return 0;
}

output--

0
1
0
1
0

When the expression was true, we got 1 and when false, 0.

3)---------------------------------- Logical operators---------------------------------

The symbol for AND is && while that of OR is ||.

Operator	Description	Example
&&	Logical AND. If both the operands are non-zero, then the condition becomes true	(a == b) && (a==8) is false
||	Logical OR. If any one or both the operands are non-zero, then the condition becomes true	(a != b) || (a==5) is true
!	Logical NOT. It is used to reverse the condition. So, if a condition is true, ! makes it false.	!(a==5) is true

Example:---

#include <stdio.h>
int main()
{
    int a = 5, b = 0;
    printf("\n%d", a && b);
    printf("\n%d", a || b);
    printf("\n%d", !a);
    printf("\n%d", !b);
    return 0;
}

output:--

0
1
0
1

Since a is non-zero but b is zero, so AND between them will be false (or 0). As only one of them is true (or non-zero). But with OR, since anyone of them (i.e. a) is non-zero, so, a||b is true (or 1 ).

In this example, since the value of 'a' is non-zero, therefore it is true. So, !a makes it false. The case with !b is the opposite.