Programming Lanuages

Programming Lanuages

1. Types of code:

   • High level code.
     • High-level code is a computer programming language based on natural languages or mathematical notation
       • The difference between these cods is that High-level is based on a real language or math notation whereas Machine code is only Binary strings.
   • Machine code
     • Machine code is the set of Binary instructions that are used by the CPU to perform a task
       • It is not readily understandable as it is written in long Binary Strings. Machine language is dependent on the processor that is using it. In each case the processor reads a Binary instruction and interprets to perform simple operations

2. Translators

   • A Translator is a needed piece of software because it converts High-level code or Assembler code into Machine code. This is necessary because the processor can only understands Machine code, With this translator the processor can understand and carry out instructions.

3. Characteristics

   • Assemblers
     • An Assembler uses source code that is written in assembly language, which is a series of memorable mnemonics used to represent machine operational codes. The Assembler will translate the source code into the Machine code form, for the computer to run.
       • The advantage of using this language is that it is a n efficient low-level language that can be translated quickly because it works on a one-to-one relationship with the Machine code.
   • Compilers
     • The source code that is written by a programmer is not understandable by the computer. A software called a complier converts the source code to object code, which is a code the computer can run on.
       • The object code is converted to match the target computer that will run the software
       • The advantage of using a complier for a high-level code language is that an executable file is produced which runs without the need for the source code. This makes the source cod more secure as it does not need to be distributed to the comustomer.
       • A disadvantage is that the compilation of a large program takes a long time to complete and any errors in the original source code need to be corrected before an executable file can be produced. So if any errors are found then it is necessary to correct them and recompile the source code.
   • Interpreters
     • Interpreter software will uaualy execute the source code directly, avoiding the need to compile the program. But it will run slower than compiled software as statement in the program is analysed before it is executed.
     • Advantages of using an interpreter is that during the development of the program the programmer may make many changes. these changes can be tested without the need of going through the time consuming processe of compiling and linking for each change made.
     • Disadvantages of interpreters are that it will need to be loaded onto the target computer and wil then need to create effient machine code at runtime. Also the source code is available to the consumer and the lin-by-line translation take a longer period of time than a compile program to run

4. Integrated Development Environment

   • Common Tools:
     • Different windows to show different parts of the program:
       • A window to show the MainForm in the design view
       • A window to display properties of a selected object (the DataView button)
       • A window to provide navigation of the main componnets of the project
     • DeBug tools:
       • Single-Step
         • This de-bugger works through the program code one line at a time. The programmer can view related data before and after the execution to help them locate problem areas within the code much easier
       • Watch
         • Watch monitors variables to see what value they are changing, this can be useful in both tracking down Run-Time and Logical Errors where a variable might occasionally be assigned an unexpected result
       • Breakpoints
         • These can be added to a program by the debugger. The will simply stop the program at a selected point, this allows the developer to gain knowledge of how the program is operating and to inspect variables or to locate errors.