Variables, input and output

Variables, input and output

What is a variable?

• A way of labeling data with a descriptive name, so our programs can be understood more clearly by the reader and ourselves.

• It is helpful to think of variables as containers that hold information. 
  

• Their sole purpose is to label and store data in memory. This data can then be used throughout your program.

Variable declarations / assignments:

• Assume two numbers; 5 and 6 are given. 

• If we were to declare two variables to store these values, they would be: 
  

• Number1 ← 5  
  

• Number2 ← 6
  

• Assume radius of a circle is 10 and we are asked to calculate the circumference of this circle.

• The variables we would use: 

• Radius ← 10
  Circumference ← 2 * PI* Radius
  PS: See there is no space used in any variables.