Introduction
A relational operator is an operator that tests a relation between two entities. The result of a relational operator is either true or false.

There are 6 relational operators in Arduino IDE:
Relational Operators | Operator Symbol | Example |
---|---|---|
Greater than | > | currentYear > 2015 |
Less than | < | 2015 < currentYear |
Greater than or equal to | >= | currentYear >= 2017 |
Less than or equal to | <= | 2017 <= currentYear |
Equal to | == | centuryYear == 2000 |
Not equal to | != | centuryYear != 1999 |
Greater than (>)
It results in true only if the first number is greater than the second number. If the first number is equal to or less than the second, it results in false. Given below is an example:
The result of the operation will be:
Is 7 greater than 4: 1
Is 7 greater than 10: 0
Less than (<)
It results in true only if the first number is less than the second number. If the first number is equal to or greater than the second, it results in false. Given below is an example:
The result of the operation is:
Is 7 less than 4: 0
Is 7 less than 10: 1
Greater than or equal to (>=)
It results in true if the first number is either greater than or equal to the second number. If the first number is less than the second, it results in false. Given below is an example:
The result of the operation is:
Is 7 greater than or equal to 10: 0
Is 7 greater than or equal to 7: 1
Less than or equal to (<=)
It results in true if the first number is either less than or equal to the second number. If first number is greater than the second, it results in false. Given below is an example:
The result of the operation is:
Is 7 less than or equal to 4: 0
Is 7 less than or equal 7: 1
Equal to (==)
It results in true only if the first number is equal to the second number; otherwise, it results in false. Given below is an example:
The result of the operation is:
Is 7 equal to 10: 0
Is 7 equal to 7: 1
Not equal to (!=)
It results in true if the first number is not equal to the second number; otherwise, it results in false. Given below is an example:
The result of the operation is:
Is 7 not equal to 10: 1
Is 7 not equal to 7: 1