Getting Started With Arduino

Arduino Basics

Making Light Patterns

IF Statement

The if statement is the first control structure.Here is an example of a programming using it:

        

                                                                listing 1.1: blink_if

int delayTime = 1000;

There is no const keyword because this is not a constant.It is a variable(which means its value can change or vary during the program).

delayTime = delayTime - 100;

Here we are changing the value of delayTime by subtracting 100 from it's original value.Since original value was 1000,after this happens the new value will be 900.

if(delayTime <= 0)

{

delayTime = 1000;

}

The purpose of this selection is to make sure the light always blinks.Since we are subtracting 100 from delayTime, we want to keep it from becoming 0 or negative.

The last section of programming turns the led on and off.