programming basics

programming basics

1. data types

   • programming languages have 5 main data types
     • casting is used to change the data type
       • languages have functions that let you manually covert between data types.
         • using the correct data type for different variables

2. the basic arithmetic operators and straightforward

   • the arithmetic operators take two values and preform a maths function on them
     • addition, subtraction, multiplication and division operators do what you'd expect

3. data types

   • integer~ whole numbers only
     • real~ numbers that have a decimal part
       • boolean~ can only take one or two values, usually true or false
         • character~ a single letter, number, symbol
           • string~used to represent text, it is a collection of characters

4. strings

   • x.upper~ changes all characters in string x to upper case
     • x.lower~ changes all characters in string x to lower case
       • x.length~ returns the number of characters in string x
         • x[i]~ extracts the character in position i from string x
           • x.subString(a, b)~extracts a string starting at position a with length b from string x

5. programs let you manipulate strings in a variety of ways

   • the characters in a string are usually numbered starting at 0
     • alphanumeric~ (letters, numbers, spaces, symbols, etc)

6. program flow

   • if statements usually have an IF~THEN~ELSE structure
     • nested IF statements allow multiple outputs
       • IF and CASE statements

7. boolean operators

   • AND~3<5 AND 2>1
     • OR~ 1>8 OR 2 == 2
       • NOT~ NOT(5>8)
         • boolean operators can be used in conditions