Arduino IDE: Comparison or Relational Operator

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.

In programming, true is represented by ‘1’, and false is represented by ‘0’.

There are 6 relational operators in Arduino IDE:

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 a false. Given below is an example:

int Result1;
int Result2;

void setup() {
 Serial.begin(9600);
 Result1 = (7 > 4);
 Result2 = (7 > 10);
 Serial.print("Is 7 greater than 4: ");
 Serial.println(Result1);
 Serial.print("Is 7 greater than 10: ");
 Serial.println(Result2);
}

void loop() {
}

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 a false. Given below is an example:

int Result1;
int Result2;

void setup() {
 Serial.begin(9600);
 Result1 = (7 < 4);
 Result2 = (7 < 10);
 Serial.print("Is 7 less than 4: ");
 Serial.println(Result1);
 Serial.print("Is 7 less than 10: ");
 Serial.println(Result2);
}

void loop() {
}

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 a false. Given below is an example:

void setup() {
 Serial.begin(9600);
 Result1 = (7 >= 10);
 Result2 = (7 >= 7);
 Serial.print("Is 7 greater than or equal to 10: ");
 Serial.println(Result1);
 Serial.print("Is 7 greater than or equal to 7: ");
 Serial.println(Result2);
}

void loop() {
}

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 the first number is greater than the second, it results in a false. Given below is an example:

int Result1;
int Result2;

void setup() {
 Serial.begin(9600);
 Result1 = (7 <= 4);
 Result2 = (7 <= 7);
 Serial.print("Is 7 less than or equal to 4: ");
 Serial.println(Result1);
 Serial.print("Is 7 less than or equal to 7: ");
 Serial.println(Result2);
}

void loop() {
}

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:

int Result1;
int Result2;

void setup() {
 Serial.begin(9600);
 Result1 = (7 == 10);
 Result2 = (7 == 7);
 Serial.print("Is 7 equal to 10: ");
 Serial.println(Result1);
 Serial.print("Is 7 equal to 7: ");
 Serial.println(Result2);
}

void loop() {
}

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:

int Result1;
int Result2;

void setup() {
 Serial.begin(9600);
 Result1 = (7 != 10);
 Result2 = (7 != 7);
 Serial.print("Is 7 not equal to 10: ");
 Serial.println(Result1);
 Serial.print("Is 7 not equal to 7: ");
 Serial.println(Result2);
}

void loop() {
}

The result of the operation is:

Is 7 not equal to 10: 1


Is 7 not equal to 7: 1

Conclusion

In this lesson, we discussed the six relational operators available in the Arduino IDE. We can use these operators to compare two values and get a boolean (true or false) result. We also looked at examples of how to use each operator. With this knowledge, you can now use relational operators in your own projects.