Programming

Programming

1. IDE

   • Editor: this allows a programmer to enter and edit source code
   • Automatic formatting: Correctly indents code
   • Automatic colour coding: Changes key words, literals and annotation to different colours
   • Linker: this is a program which allows previously compiled code, from software libraries, to be linked together
   • Loader: this is a program which loads previously compiled code into memory.
   • Debugger: this is a program which helps locate, identify and rectify errors in a program
   • Syntax error detection: Highlighting syntax errors before code is translated
   • Trace: this is a facility which displays the order in which the lines of a program are executed, and possibly the values of variables as the program is being run
   • Break point: this is a facility which interrupts a program on a specific line of code, allowing the programmer to compare the values of variables against expected values. The program code can then usually be executed one line at a time. This is called single-stepping
   • Variable watch: this is a facility which displays the current value of any variable. The value can be 'watched' as the program code is single-stepped to see the effects of the code on the variable. Alternatively a variable watch may be set, which will interrupt the program flow if the watched variable reaches a specified value
   • Memory inspector: this is a facility which will display the contents of a section of memory
   • GUI creation: Allows programmer to create a GUI by dragging and dropping controls (buttons, etc...) onto a form.

2. Variables

   • Local - used within a sub-routine
   • Global used Throughout the whole program

3. Errors

   • Syntax
     • Incorrect: IF A ADN B Then Correct: IF A AND B Then
   • Semantic
     • Attempting to assign incorrect data type integer = real
   • Runtime or Execution
     • Division by zero Reading past end of file or out of memory
   • Logical
     • Count = Count – 1 should be Count = Count + 1
   • Linking
     • When the Square Root function is used and the library that calculates the Square Root has not been linked to the program
   • Rounding
     • 34.5 rounded to nearest whole number is 35, an error of +0.5.
   • Truncation
     • 34.9 truncated to whole number is 34, an error of -0.9.

4. Compiler

   • A compiler translates the whole program in one go
   • A compiler produces an executable file that will run on the target hardware machine without the compiler being installed
   • Compilers tend to be large complex programs
   • Compiled programs have to be re-compiled after a change

5. Interpreter

   • An interpreter translates each line of code (often an intermediate code) at run time
   • Interpreters are smaller simpler programs
   • Interpreted programs can be amended and run without translating whole program

6. Assembler

   • Compiled programs have to be re-compiled after a change