2.2 Programming Techniques

2.2 Programming Techniques

1. Sequence, Selection and Iteration

   • Sequence: Completing steps in the order which they must happen
   • Selection: Where a choice is made in a program depending on a condition or outcome
   • Iteration: Act of repeating or looping specific sections of code Count controlled Iteration: Repeats a set number of times Condition controlled: Repeats until a condition is met or something in the program changes

2. Logic, Syntax and Run Time Errors

   • Syntax Error An error in the rules/grammar of the language Eg missing colon / spelling mistake
   • Logic Error The program is written to do something other than what the programmer intended Eg Resetting only the first 9 elements in an array instead of all 10.
   • Run Time Error: More difficult to spot as it can run a program without reporting an error. E.g. runs but Doesn’t give an output. Or the program hangs or Becomes inactive

3. Data Types

   • Real /Float: Number with decimal Point
   • Integer: Number without a decimal Point
   • String: A series of characters/TEXT
   • Character: A single letter or symbol
   • Date/Time: Date and Time in any format
   • Boolean: Yes no, true false value

4. Other Things

   • Validation: An computer check to ensure that the data entered is sensible and reasonable. It does not check the accuracy of data.
   • Comments Use these to add comments in to your code to explain what you have done
   • Concatenate To join different data types together

5. Variable Declaration

   • In some programming languages, variables need to be declared before they can be used to store data.
   • Declaring a variable means to state its name (identifier) and the type of data that it will contain, for example
   • Python also doesn't require that the type of data being stored is stated, it simply infers the data's type from the data that is assigned to (stored in) the variable.
   • Python doesn't require that variables are explicitly declared before they are used. Instead, they are automatically declared upon first use.