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Chapter 4 - Programming Operator

Operators are symbols that carry out a specific function. For example '*' multiplies two numbers.

Arithemtic Operators​

Arithemetic operators carry out mathematical operations like multiplications, division, addition and subtraction.


Let’s try using your Arduino board.

  • In your Arduino IDE try dividing 2 integers whose answer is a decimal (Eg: 9/4, 8/7 and 10/56). What do you notice?
  • Even though the answer is a floating-point number, it is changed to an integer because the 2 variables used are integers.
  • Try it again using floating points instead.

Assignment Operators​

Assignment operators are used when assigning a value to a variable. The most commonly used assignment operator is the equal sign (=).

+=a+=ba = a+b
-=a-=ba = a-b
*=a*=ba = a*b
/=a/=ba = a/b
%=a%=ba = a%b
The symbol '%' returns the remainder of an equation.

if a = 11 and b = 5
Then a%=b will return 1 because 11/5 = 2 R 1

Using your own Arduino board, try the following:

Create different expressions using assignment operators.

void setup(){
int a = 5;
int c = a;
//Instead of using variable names such as a, b and c,
//try using other names such as counter, num and temp
int num = 5;
int temp = num;

void loop(){


Relational Operators​

A relational operator verifies the relationship between two variables. If the statement is proven to be true then the output will be 1, if the statement is false then the output will be 0.

==Equal to22 == 4; false return = 0
>Greater than22 > 4; true return = 1
<Less than22 < 4; false return = 0
!=Not equal to22 != 4; true return = 1
>=Greater than or equal to22 >= 4; true return = 1
<=Less than or equal to22 <= 4; false return = 0

Logical Operators​

OperatorMeaningExample (c=5, d=3)
&&Logical and true only if all operands are true.((c==5) && (d==3)); false return = 0
||Logical and only true if one operand is true((c==5) || (d==3)); true return = 1
!Not Logical true only if the operand is 0!(c==5); false return = 0

AND is a word used to add an additional comment or condition

OR is used to describe an alternative choice



  1. Start by creating 3 variables with different values. (for more challenges try using three different types, int, float and double).
  2. Using arithmetic operators create an expression where the output will be 3.
  3. Then using any relational operator create an expression where the output will be 1.
  4. Use any logical operator to return the value of 0.