# IntVariable.py
# demo an int variable storing a value and varying its value.
# to "understand the quintessence of programming."

# Programs process data.
# All data in all programs in all the world is stored in variables.
# E.g. everything you type, click, swipe, say, see, be at, go, feel.
# Everything you read, see, hear at every website and app.
# Everything in every corporate and government database.

# create a variable and assign 12 to be its value:
students = 12
  
  #think of a variable as a little box in the computer but it's actually
  #  a named location in memory (RAM).
  #its name is students.  
  #it can store/hold one value, which now is the integer 12.
  #names of variables can consist of letters, digits and _ but
  #  cannot start with a digit.  name should be meaningful,
  #  indicating what the variable is used for, what its purpose is.

  # = is the "assignment" "operator".
  #it is an action, not an equation.  leftside must be a variable,
  #rightside an expression.  rightside is evaluated, then that (single) 
  #value is assigned to be the value of the leftside variable.

print("variable is now: ", students)
  
students = students + 1       #add one to the students variable.
  #assign its current's value plus one as its new value.
  #rightside is students+1     students is 12, so it's 12+1 which is 13,
  #so 13 is assigned to leftside variable
print("and now it's: ", students)

#Variables is a fundamental notion in programming.

# Another fundamental notion:
#You are specifying a sequence of commands, directives, or "statements" that the computer is to do.
# Essentially this Python environment is the computer. It's a machine that understands Python.

# You are creating the activity that happens.