Programming Techniques

Programming Techniques

1. Flow Charts

   • Algorithm flowcharts are sets of clearly defined rules to process data. Devising a set of algorithms to solve a problem is the most important part of the process. Well-defined algorithms will lead to well-constructed and effective programs. Algorithms can be defined in many ways, including program flowcharts of pseudocode.

2. Pseudocode

   • Pseudocode is a language used to define alogrithms that is close to both English and program code. Once we have the flowchart to outline how the solution should work, we can start to turn this into a format we can code.
   • We use pseudocode to define our algorithm in a format that will easily translate into program code, but does not require us to use precise detail of the programming language. The pseudocode simply outlines the steps in our program to achieve a working solution.
   • The pseudocode defines the logic of the problem to be solved before we develop the actual code to solve the problem. The pseudocode defines the structure for the actual code, but does not need to include all the syntax required by our programming language.

3. Sequence And Selection

   • The simplest type of program consists of a sequence of instructions to be carried out in the order they are written.
   • Allowing only such simple control structures would limit what we could write, and we need to introduce more complex pathways through programs including selection and iteration.

4. Iteration

   • If we need to repeat a block of code several times, we use of the various iterative structures available in most programming languages.

5. Data Types

   • A variable is a named location where we store data. We need to identify some standard data types so that a program can reserve appropriate locations for the data. There are several data types we need to use within a program and these have different storage and handling requirements.
   • These data types are as follows: Integer, String, Boolean, Character, Real

6. Arrays

   • An array is used when we require a number of variables to store similar data with. An array is a single name given to a block of variables with an index value.
   • One important fact about arrays is that we do not have to refer to the values individually. We can use a variable index value to look at individual items.

7. Numerical Operations

   • When we process data in our program, we often need to use standard mathematical operations. Various languages use different symbols for the operations.
   • It is important that we get the result we want and these operations are applied in a strict order to produce consistent results. The order in which the other operations are performed makes a big difference.

8. Strings

   • There are a number of functions that can be used to manipulate a string variable. These functions can identify the length of individual parts of the string, and can convert case or convert between a character and it's ASCII value.

9. Machine And Low Level Code

   • Computers use machine code. Machine code uses binary and it is almost impossible for humans to understand programs written in machine code. Machine level languages need to manipulate the machines architecture and are different for different CPU's.
   • In low level languages, every action of the processor has to be coded.To add together two numbers, the program has to go through each step of the process.

10. High Level Language

    • High level languages use instructions close to English and have complex structures. One instruction in a high level language can be equivalent to many machine code instructions. High level languages use translators to make them machine dependable.
    • Compilers translate high level language commands into a single executable code program. A compiler will translate a computer program into machine code that executes at a later time. There is no need for the translator to be running on the target machine.