2.5- Languages and IDEs

Low Level Language

Low Level Language

A language that is close to what a CPU would actually do and written for specific hardware

Examples of low level language

• machine code

• assemble language

Machine Code

the lowest level programming language consisting of 0s and 1s. CPUs can directly process it as a string of CPU instructions. 1st generation

pros of machine code

• more flexibility with commands

• commands can be directly executed without a translator

• faster to process as CPU doesn’t have to translate

• more memory efficient

cons of machine code

• usually written for 1 type of machine or processor- wont work on others

• very hard for programmers to read and understand

• programmer requires knowledge of internal structure of CPU

Assembly Language

2nd generation language that uses mnemonics to form instructions. Each mnemonic corresponds with a machine code instruction.

pros of assembly language

• much easier to read and understand that machine code

• more accessible to programmers

cons of assembly language

• not as easy to use as high level languages

• requires translation

• requires an assembler

high level languages

3rd gen programming languages that are easy for humans to understand

examples of high level languages

• python

• java

• C++

pros of high level languages

• one instruction of high level=many instructions of machine code

• portable- same code works for many different machines and processers

• easy for programmer to store data (e.g. in arrays) without knowledge of memory structure

• code is close to english so is easy to read and understand

cons of high level languages

• must be translated for computer to understand

• programs are less memory efficient and slower to execute

translator

a program that allows source code to be understood and executed by the computer

types of translator

• compiler

• interpreter

compiler

type of translator that translates all of the source code at once and creates one executable file

pros of compiler

• only required once to create executable file

• returns a list of errors for the entire program once compiling is complete

• once compiled program runs quickly

cons of compiler

• compiling can take a long time, so program isn’t immediately executed

• not good for debugging

interpreter

translates and runs the source code of one instruction at a time

pros of interpreters

• will return first error it finds and then stop-good for debugging

• more immediate execution of the program

cons of interpreters

• doesn’t create an executable file

• needed every time you want to run the program

• programs will run more slowly

IDE

Integrated Development Environment- A piece of software to help a programmer develop programs

features of IDEs

• code editor

• run-time environment

• error diagnostics and debugging tools

• breakpoints

• translator

• GUI

Code Editor

• where code is written

• will usually have:

  • line numbering

  • colour coding

  • auto-correct

  • auto-indentation

  • auto-complete

runtime environment

allows code to be run quickly within IDEs- done using start/run button.

can help identify logic errors as programmer can see which part of code is running when errors occur.

GUI

helps programmer design a user interface by building it up graphically rather than having to design it using source code.