Conditional statements allow an Arduino program to make decisions based on whether a condition is true or false.

3.4.1 if Statement

The if statement executes a block of code when a specified condition is true.

if (temperature > 30) {

  digitalWrite(13, HIGH);

}

If the temperature is greater than 30, the LED is switched on.

3.4.2 if…else Statement

The if…else statement provides two possible actions.

if (temperature > 30) {

  digitalWrite(13, HIGH);

} else {

  digitalWrite(13, LOW);

}

If the temperature is above 30°C, the LED turns on; otherwise, it turns off.

3.4.3 if…else if…else

This structure is useful when several conditions need to be checked.

if (temperature > 35) {

  Serial.println(“High temperature”);

} else if (temperature > 25) {

  Serial.println(“Normal temperature”);

} else {

  Serial.println(“Low temperature”);

}

3.4.4 switch…case

The switch statement is useful when a variable can have several specific values.

int option = 2;

 

switch (option) {

  case 1:

    Serial.println(“LED”);

    break;

 

  case 2:

    Serial.println(“Motor”);

    break;

 

  case 3:

    Serial.println(“Buzzer”);

    break;

 

  default:

    Serial.println(“Invalid option”);

}

The break statement stops the program from continuing into the next case.