SLR 2.5 Translators and facilities of languages

Question 1

What is ‘source code’?

Answer 1

It is the high level language code written by programmers (for example code in Python, C#, C++ etc.)

Question 2

What is ‘machine code’?

Answer 2

It is the binary code representation of instructions that the CPU can decode and execute (once fetched)

Question 3

Why do programmers code in high level languages?

Answer 3

• high level languages are human readable
• high level languages can be translated to many different architectures / platforms
• high level languages take fewer lines of code to write

Question 4

What is the role of an interpretter?

Answer 4

It translates a high level language such as Python, C++ etc. into machine code (binary) one line at a time at run time (when the code is executed)

Question 5

What is the role of a compiler?

Answer 5

It translates a high level language such as Python, C++ etc. into machine code (binary) all at once. It produces compiled code which executes very quickly.

Question 6

What is the role of an assembler?

Answer 6

It translates assembly code into machine code

Question 7

What is the relationship between instructions in assembler and instructions in machine code

Answer 7

• there is a one-to-one (1:1) relationship between assembler instructions and machine code instructions.
• both have opcodes and operands

Question 8

What type of code is represented below:
1001 0001
0001 0110
0011 0111

Answer 8

Machine code

Question 9

What type of code is represented below:
INP
ADD 7
STA 99

Answer 9

Assembly code

Question 10

What type of code is represented below:

result = input(“Enter the result”)

Answer 10

Source code

Question 11

What is an IDE?

Answer 11

an Integrated Development Environment

Question 12

What are the features of an IDE?

Answer 12

code completion
code colouring
auto-indentation
debugging
run-time environment
syntax error highlighting

Question 13

Describe two advantages of using a compiler instead of an interpreter

Answer 13

• The compiled code will run more quickly…
• …because the instructions only need to be translated once.
• …because the compiler optimises the code.
• Source code cannot easily be reverse engineered.
• …so is more easily protected from being copied.
• No translation software is required at runtime.