Datasheet
Your Shield-Bot’s Brain • Chapter 1
Robotics with the BOE Shield-Bot • 31
void setup()
{
Serial.begin(9600);
int a = 89;
int b = 42;
if(a > b)
{
Serial.print("a is greater than b");
}
}
Maybe your sketch needs to monitor for three conditions: greater than, less than, or equal.
Then, you could use an
if…else if…else statement.
if(a > b)
{
Serial.print("a is greater than b");
}
else if(a < b)
{
Serial.print("a is not greater than b");
}
else
{
Serial.print("a is equal to b");
}
A sketch can also have multiple conditions with the Arduino's Boolean operators, such as &&
and
||. The && operator means AND; the || operator means OR. For example, this
statement’s block will execute only if
a is greater than 50 AND b is less than 50:
if((a > 50) && (b < 50))
{
Serial.print("Values in normal range");
}
This example prints the warning message if a is greater than 100 OR b is less than zero.
if((a > 100) || (b < 0))
{
Serial.print("Danger Will Robinson!");
}
One last example: if you want to make a comparison to find out if two values are equal, you
have to use two equal signs next to each other:
==.