2.5

Question 1

What is a compiler? (2)

Answer 1

• Translates source code from high level languages into object code then into machine code
• Whole program is translated into machine code before run

Question 2

What are the advantages of a compiler? (4)

Answer 2

• No need for translation software at run-time
• Faster execution speed
• Code is optimised
• Source code is secret

Question 3

What are the disadvantages of a compiler? (3)

Answer 3

• Will not run with syntax errors (hard to debug)
• Code needs to be recompiled when the code is changed
• Designed for a specific type of processor

Question 4

What is an interpreter? (2)

Answer 4

• Translates source code from high-level languages into machine code
• Translated line by line as the program is running

Question 5

What are the advantages of an interpreter? (3)

Answer 5

• Easy to write source code, program will always run, until it finds a syntax error
• Code does not need to be recompiled when code is changed, easy to try out commands when the program has paused after finding an error
• Interpreted languages are easy for beginners to learn to write code

Question 6

What are the disadvantages of an interpreter? (4)

Answer 6

• Translation software is needed at run-time
• Slower execution speed
• Code is not optimised
• Source code is needed

Question 7

What is a high level language? (9)

Answer 7

• Source code is aimed at humans
• Structure and syntax similar to English
• Must be translated to machine code by a compiler/interpreter
• Works on different types of processors
• Easy to write and understand code
• Less memory efficient
• Slow execution if not optimised
• One source code = multiple machine code instructions
• e.g. python, java, c++

Question 8

What is machine code? (2)

Answer 8

• Uses binary
• Represents instructions in a format the CPU can decode and execute

Question 9

What is a low-level language? (8)

Answer 9

• Translated by an assembler into machine code
• Used for embedded systems/device drivers (instructs hardware directly)
• One source code instruction = one machine code instruction
• Works on only one type of processor
• Works directly with memory
• Harder to write and understand code
• Fast to execute
• e.g. machine code, assembly language

Question 10

What do translators do? (3)

Answer 10

• Translates source code written in a high level language into machine code
• Translates assembly code written in a low level language into machine code
• e.g. compiler, interpreter, assembler

Question 11

What does an Integrated Development Environment (IDE) include?

Answer 11

• Code editors to enable program code to be entered
• Error diagnostics for debugging
• Run-time environment to test and run the program
• Translator to convert high level code to machine code

Question 12

What are the editing features of an IDE? (3)

Answer 12

• Illustrating keyword syntax and auto completing command entry and indentations
• Highlighting error
• Producing an output of the error message to identify it

Question 13

What are the debugging features of an IDE? (3)

Answer 13

• Breakpoints to stop code at a certain point
• Going through lines one at a time to check the lines being executed
• Tracing through a program to output the values of variables

Question 14

What are the two features of an IDE that provide a run-time environment?

Answer 14

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