If Statement (Conditional Statement)

The if() statement is the most basic of all programming control structures. It allows you to make something happen or not, depending on whether a given condition is true or not. It looks like this:

Copy
1if (someCondition) {
2// do stuff if the condition is true
3}

There is a common variation called if-else that looks like this:

Copy
1if (someCondition) {
2// do stuff if the condition is true
3} else {
4// do stuff if the condition is false
5}

There's also the else-if, where you can check a second condition if the first is false:

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1if (someCondition) {
2// do stuff if the condition is true
3} else if (anotherCondition) {
4// do stuff only if the first condition is false
5// and the second condition is true
6}

You'll use if statements all the time. The example below turns on an LED on pin 13 (the built-in LED on many Arduino boards) if the value read on an analog input goes above a certain threshold.

Hardware Required

• Arduino Board

• Potentiometer or variable resistor

Circuit

Schematic

Code

In the code below, a variable called

analogValue

<

Learn more

You can find more basic tutorials in the built-in examples section.

You can also explore the language reference, a detailed collection of the Arduino programming language.

Last revision 2015/07/29 by SM