2.5 Programming Languages and IDEs

Question 1

What is machine code?

Answer 1

• Binary representation of instructions in a format that the CPU can decode and execute
• Have operation code instruction and address or data to use

Question 2

What are low level languages?

Answer 2

• Written in Assembly language
• Translated by an assembler into machine code

Question 3

What are low level languages used for?

Answer 3

• Used for embedded systems and device drivers where instructing hardware directly is necessary

Question 4

What are some features of low level languages?

Answer 4

• Harder to write and understand
• Memory efficient
• Fast to execute

Question 5

What are high level languages?

Answer 5

• Source code written in languages such as Python, C++, Java, Visual Basic

Question 6

What are high level languages translated by?

Answer 6

• Translated by compiler or interpreter into machine code

Question 7

What does one source code instruction in a high level language translate to?

Answer 7

• Translates to many machine code instructions

Question 8

Features of High level languages?

Answer 8

• Quicker and easier to understand and write
• Less memory efficient
• Could be slower to execute if not optimised

Question 9

What does a compiler do?

Answer 9

• Translates source code from high level languages into object code and then into machine code ready to be processed by the CPU
• Whole program is translated to machine code before it is run

Question 10

What are the advantages of a compiler?

Answer 10

• No need for translation software at run-time
• Speed of execution is faster
• Code is usually optimised
• Original source code kept secret

Question 11

What are the disadvantages of a compiler?

Answer 11

• Program won’t run with syntax errors, making it more difficult to write the code
• Code needs to be recompiled when it is changed
• Designed for a specific type of processor

Question 12

What does an interpreter do?

Answer 12

• Translates source code from a high level language into machine code ready to be processed by CPU
• Program is translated line by line while running

Question 13

What are the advantages of an interpreter?

Answer 13

• Easy to write source code as it’s always running, stopping when finding a syntax error
• Code doesn’t need to be recompiled when changed
• Interpreted languages made very easy for beginner programmers

Question 14

What are the disadvantages of an interpreter?

Answer 14

• Translation software is needed at run time
• Speed of execution is slower
• Code not optimised
• Source code needed

Question 15

What functions do IDEs provide?

Answer 15

• Debugging tools for finding logic errors
• Help with preventing and identifying syntax errors
• Providing a run time environment
• Usability functions

Question 16

How does an IDE help debug tools for finding logic errors?

Answer 16

• Breakpoints - stopping program at line of code during execution
• Stepping through lines of code one at a time to check which lines are executing
• Tracing through a program to output values of variables

Question 17

How does an IDE help with preventing and identifying syntax errors?

Answer 17

• Illustrating keyword syntax and auto completing command entry
• Error highlighting
• Compiler producers an output of the error message to help identify it

Question 18

How does an IDE provide a run time environment?

Answer 18

• Output window
• Simulating different devices the program can run on

Question 19

What usability functions does an IDE provide?

Answer 19

• Navigation, showing/hiding sections of code
• Formatting source code
• Find and replace
• Comment or indent regions