Relational Operators

Using relational operators in C, we compare 2 values. The comparison could be if 2 values are equal or not equal, if one value is greater than another, or lesser than another. The values can be of type int, float, double, long or char. The result of the comparison will be 0 or 1., result 0 signifies false, and 1 signifies true.

There are 6 types of relational operators, == (equals), != (not equals), > (greater than), >= (greater than or equal), < (less than), < (less than or equal).

Equals Operator

We use equals operator to compare if two values are equals.

int a = 5, b = 10;
printf("%d", a == b);  //prints 0

The equals operator consists 2 equal symbols. If you by mistake write only 1 equal, it will become an assignment operation.

int a = 5, b = 10;
printf("%d", a = b);  //prints 10

In the above code snippet, we are using a single equals, that’s why the operation performed on that line is an assignment not an equals comparison.

Not Equals Operator

We use a not equals operator to test if 2 values are not equal with each other. We denote it by an exclamation followed by an equal symbol.

int a = 5, b = 10;
printf("%d", a != b);  //prints 1

Greater Than Operator

We use a greater than operator to check if a value is greater than another value. We denote “greater than” operator using > symbol as we usually do in mathematics..

int a = 5, b = 10;
printf("%d", a > b);  //prints 0

Greater Than or Equals Operator

We use greater than or equals operator to check if a value is greater, if not equals with another value. To write greater than or equal, we put an “equals” operator followed by “greater than” symbol, like >=.

int a = 5, b = 5;
printf("%d", a >= b);  //prints 1

In the above code snippet, though a is not greater than b, since it is equals to b, so the result will be 1.

Less Than Operator

We use a less than operator to check if a value is less than another value. We denote “less than” operator using the less than symbol <.

int a = 5, b = 5;
printf("%d", a < b);  //prints 0
printf("%d", a < 9);  //prints 1

Less Than or Equal Operator

We use “less than or equal” operator to test if a value is less than another value or equal to itself. We denote “less than or equal” operator using less than symbol followed by equal symbol.

int a = 5, b = 5;
printf("%d", a <= b);  //prints 1
printf("%d", a < 2);  //prints 0