Programming Languages based on Typing

• Static-Type:
  • Developers need to specify data type before using variables
  • Eg: C, C++, Java etc
• Dynamic-Type:
  • Developers need not specify data type, data types are decided by interpreter/compiler depending on data passed to it.
  • Eg: Shell, Ruby, Python

Program1: Calculate compound intrest

• Python program to calculate compound intrest

principle = 10000.0
time = 10
rate_of_intrest = 10
compound_intrest = principle * ( 1+(rate_of_intrest/100))**time
print(compound_intrest)

• Getting one level deeper with the execution. Open Python shell and execute the above program line by line and also add few stuff in between every statement
  • Check value
  • Check type (type())
  • Check memory location (id())

Memory layout of the following statements

• Initial Lines

time = 10
rate_of_intrest = tim

• Lets make some changes

time = time + 1

• Now lets execute

message = 'hello'

• one more change

message = 'hi'

Learnings from above experiments

• In python basic data types such as int, float, str, bool are immutable i.e. whenever you change value a new memory is allocated and variable will point to new memory location.

Operators

• Two kinds of operators

  • Binary Operators
    • Require two operands
  • Unary Operators
    • Require one operand

• Google ‘python operators’ and pick any page you want

• Operators might change the behavior depending on type of data which we use or operate on

value = 5
value * 2
# 10

value = 'hi'
value * 2
# 'hihi'

• Experiment with Arthimetic , Assignment and comparision operators from here