2.5- Languages and IDEs

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.