Chapter 2 Programming

• str()

  text called a string
• int()

  whole number called an integer
• float()


  decimal number called a float
• TRUE/FALSE

  Boolean variable
• ==

  is equal to
• <=

  is less than or equal to
• >

  greater than
• !=

  not equal to
• Iteration

  a loop,repeat
• Definite loop

  when you know how many times you want to loop for...
• Indefinite loop

  when you don't know how many times you want to loop.while...
• if

  if=selection
• comments


  explains what each part of the program does;easier to read
• Descriptive names

  descriptive identifier for variavles/constants/subprograms to make their purpose clear.
• Indentation

  easier to see where each block of code starts and finishes.Getting this wrong could also reuslt in the program not running.
• White space

  adding blank lines between bits of code to make them stand out.
• Strings

  A sequence of characters.They can be letters,numbers,symbols,punctuation or spaces ususally put in speech marks.Substring is a way of extracting part of the string.The substring is also known as a slice.
• Sub programs

  A piece of code that performs a specific task.
• Example of sub program

  Turtle is a built in subprogram
• Recursion

  when subprograms call themselves.You must have a terminating condition otherwise this creates an infinite loop.
• Functions

  This returns a value to the main program
• Procedures

  This doesn't return a value to the main program
• Parameters

  The values that are passed to a subprogram when it is called.
• Constant

  a set value that can not be changed
• Local variable

  only accesses from the subprogram in which it is created
• Global Variable

  can be accessed from anywhere in the program including inside subprograms
• Scope

  the region of code within a variable is visible(where can that variable be seen-local or global)