2.2 Programming

2.2 Programming

1. Sequence keywords

   • Boolean is a data type that can only only have two values, this makes it especially useful for TRUE/FALSE.
   • An arithmetic operator is a mathematical function that takes two operations and performs a calculation on them
     • ^ (Exponenention) means to the power of eg, 3^4 = 81
     • Modulus (MOD) is the remainder after an integer division eg 12 MOD 5 = 2
     • Quotient(DIV) is the number of times the divisor fits in the number ie 11 DIV 3 = 3
   • a string is any finite sequence of characters (i.e., letters, numerals, symbols and punctuation marks). An important characteristic of each string is its length, which is the number of characters in it.
   • Concatenation is the operation of joining two strings together.
   • Constants are values that don't change as the program runs.
   • a variable is a value that can change, depending on conditions or on information passed to the program
   • Memory addresses are tied to data, this address is often a hexadecimal or binary address, of which show to location
   • A parameter is a special kind of variable in computer programming language that is used to pass information between functions or procedures
   • Casting is converting a variable from one data type to another

2. ASCII AND UNICODE

   • ASCII is the 7 bit value associated with each letter or number oon the keyboard
     • Maximum of 127 numbers
   • UNICODE is used for further characters for example emojis. Cna be 8,16,32 bit

3. This is how to handle external files^

4. String handling

   • To get the length of a string: stringname.length
   • To get a substring:
     • stringname.subString (startingPosition, numberofCharacters)
   • Converting cases: stringname.upper stringname.lower

5. SQL

   • SQL stands for Standard Query Language, a popular human-readable programming language that is used to work with databases
   • These databases are not stored in text files or CSV files but in binary proprietary formats, of which the more common ones include MySQL, SQLlite, MsAccess, Oracle, etc.
   • SELECT*FROM Results WHERE Result > 80
     • SELECT tells it what to do in this case select all, symbolised by *
     • FROM tells it where to pull this data from
     • WHERE is the criteria in this case the result being > 80

6. Array

   • An array is a variable that can contain more than one piece of data

7. Sub programs

   • Summary
   • Example
     • "output_throw" is an example of a function. It also has a subprogram called "roll_a_dice"

8. Data types

9. Records

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