4.2 Programming Languages, translators and IDE's

Question 1

Explain what is meant by the term “high level language”

Answer 1

• Written in a form that is close to our human language
• No knowledge of hardware/architecture required
• Portable - machine independent
• Examples: C#, Python etc.

Question 2

Explain what is meant by the term “low level language”

Answer 2

• Written in a form that is close to the processor instruction set
• Knowledge of hardware/architecture is required
• Not portable - machine dependent
• Examples: assembly language and machine code

Question 3

State 3 advantages of a high level language

Answer 3

• Easier to understand for programmers
• Portable - not machine specific
• No need to understand the architecture of a computer
• One instruction equals many processor instructions
• Much easier to debug and test
• Only need to learn a single language
• Has built in libraries and functions that can be reused

Question 4

State 3 advantages of a low level language

Answer 4

• Program often requires less memory/RAM
• Can make use of special hardware
• Can use memory addresses directly
• Can be written to run faster (optimised)

Question 5

Explain two reasons why a computer programmer may choose to write a program in a high- level language, rather than a low-level language.

Answer 5

• Closer to human language/English …
  
  • …so it is easier/quicker to read/write/understand/debug
• The program can be used on many different platforms…
  
  • …because it is compiled into object code
• They have built-in functions/libraries…
  
  • …this saves time when writing the program
• Do not need to manipulate memory addresses directly…
  
  • …therefore, specialist knowledge of this is not required
• Only need to learn a single language…
  
  • …as this can be used on many different computers

Question 6

Explain two reasons why a computer programmer may choose to write a program in a low-level language, rather than a high-level language.

Answer 6

• allows direct access to computer processor / special hardware //
• machine dependent instructions uses up less memory
• can increase the speed of processing a program // executes instructions faster

Question 7

State 3 different translators

Answer 7

• Assembler
• Compiler
• Interpreter

Question 8

State a translator that can be used to translate a low level language into machine code

Answer 8

• Assembler

Question 9

State 2 different translators that can be used to translate a high level language into machine code

Answer 9

• Compiler
• Interpreter

Question 10

Describe how an interpreter translates a computer program

Answer 10

• Translates high-level language into machine code
• Translates (the source code) line by line/statement by statement
• The interpeter is used each time the code is executed
• Stops if it finds an error and will only continue when error is fixed

Question 11

Describe how a compiler translates a computer program

Answer 11

• Translates high-level language into machine code (object code)
• Translates (the source code) all at once
• Produces an executable file
• Produces an error report / list of errors
• Optimises the source code (to run efficiently)

Question 12

Describe how an assembler translates a low level language

Answer 12

• Translates (the source code) all at once
• Produces an executable file
• Produces an error report / list of errors
• Optimises the source code (to run efficiently)

Question 13

Assembly language: True or False?

• Assembly language uses mnemonic codes.
• Assembly language programs do not need a translator to be executed.
• Assembly language is a low-level programming language.
• Assembly language is specific to the computer hardware.
• Assembly language is machine code.
• Assembly language is often used to create drivers for hardware.

Answer 13

• Assembly language uses mnemonic codes. TRUE
• Assembly language programs do not need a translator to be executed. FALSE
• Assembly language is a low-level programming language. TRUE
• Assembly language is specific to the computer hardware. TRUE
• Assembly language is machine code. FALSE
• Assembly language is often used to create drivers for hardware. TRUE

Question 14

Interpreter or Compiler?

• Translates the source code into machine code all at once
• Produces an executable file in machine code
• Executes a high-level language program one instruction at a time
• Once translated, the translator does not need to be present for the program to run
• An executable file is produced

Answer 14

Translator or Compiler?

• Translates the source code into machine code all at once Compiler
• Produces an executable file in machine code Compiler
• Executes a high-level language program one instruction at a time Interpreter
• Once translated, the translator does not need to be present for the program to run Compiler
• An executable file is produced Compiler

Question 15

Interpreter or Compiler?

• A report of errors is produced at the end of translation
• The program is translated one line at a time
• The program is translated from high-level language into machine code
• An executable file is produced
• The program will not run at all if an error is detected

Answer 15

Translator or Compiler?

• A report of errors is produced at the end of translation Compiler
• The program is translated one line at a time Interpreter
• The program is translated from high-level language into machine code Compiler & Interpreter
• An executable file is produced Compiler
• The program will not run at all if an error is detected Compiler

Question 16

Why might you use a compiler rather than an intrepreter?

Answer 16

• Compiled program can be executed without a translator
• Faster execution as it is not translated line by line
• Provides an executable file therefore you cannot see the code

Question 17

Why might you use an interpreter rather than an compiler?

Answer 17

• Faster for developing software and debugging …
  
  • all of the code does not need to be translated
  • can execute code quickly (line by line)

Question 18

What is an IDE?

Answer 18

• Integrated Development environment
• A software application used by programmers that …
• … provides a range of features to support program development

Question 19

Name 3 features of an IDE

Answer 19

• Code Editor
• Translator
• Runtime environment with a debugger
• Error Diagnostics
• Auto-completion
• Auto-correction
• Auto-documenter and prettyprinting

Question 20

What is the purpose of a code editor in an IDE?

Answer 20

• Allows the program to be written without a separate text editor
• Speeds up the development process

Question 21

What is the purpose of a translator in an IDE?

Answer 21

This could be an interpreter or compiler and enables the code to be translated to machine code and executed

Question 22

What is the purpose of a runtime environment in an IDE?

Answer 22

• Often contains a debugger
• Allows the programmer to step through the code line by line
• Can set breakpoints to stop execution
• A report window shows the values of variables to check logic errors

Question 23

What is meant by error diagnostics in an IDE?

Answer 23

Dynamic error checking finds possible errors whilst writing

Shows a list of syntax errors after compilation

Question 24

What is meant by auto-correction in an IDE?

Answer 24

Underlines errors and dynamically suggests corrections as code is being typed

Question 25

What is meant by auto-completion in an IDE?

Answer 25

Code editors can offer to complete instructions and key words as they are being typed

Question 26

What is meant by an auto-documentor in an IDE?

Answer 26

An auto-documentor explains the functions and purpose of built in code

Question 27

What is meant by prettyprinting in an IDE?

Answer 27

Key words are colour coded and code is indented and structured meaningfully