2.5.1.Languages

2.5.1.Languages

by Mr. Shingari

Walt

​To be able to describe the different generations of programming language.

To be able to describe the differences between low-level and high-level languages.

To evaluate the benefits of programming in both low-level and high-level languages.

To state which translator is needed for each and why.

Open Ended

What would make code easier for a computer to understand?

What would make code easier for a programmer to write?

Open Ended

Find the error in this code:

The program should allow the user to input a value and then store it in memory address 25.

0001

1100

​Error in task

​0001                            ‘This line is fine as it allows the user to enter a value into the Accumulator

1100                            ‘This line of code is not valid as it does not specify the memory address

Open Ended

Find the error in this code:

The following program allows the user to enter a value – the number 3 is added to the value and then output. Another value is then entered and the number 1 is added to the value – this is then also output.

0001

1010 000011

0010

0001

1010 00000001

0001 00000001

​​​Task 2

0001                            ‘This is valid

1010 000011               ‘This is meant to add the value 3 – but the value is not an 8 bit Binary Number

0010                            ‘This correctly outputs the contents of the Accumulator

0001                            ‘This correctly allows input into the Accumulator

1010 00000001           ‘This correctly adds the value 1 to the contents of the Accumulator

0001 00000001           ‘This does not correctly output the contents of the Accumulator

Open Ended

Find the error in this code:

This program allows the user to enter 3 values – all the values are added together and output.

0001

1100 00010000

0001

0011 00010001

0001

1011 00010001

1010 00010000

0010

0001 00000001

​​​Task 2

0001                            ‘Correct – allows input into the Accumulator

1100 00010000           ‘Correctly stores the value in location 16

0001                            ‘Correct – allows input into the Accumulator

0011 00010001           ‘Incorrect operation code

0001                            ‘Correct – allows input into the Accumulator

1011 00010001           ‘Adds memory location 17 to the Accumulator

1010 00010000           ‘Adds the value 16 to the Accumulator

0010                            ‘Outputs the result

 

 

​

​Generations of programming languages

​

​There are several generations of Programming Languages

Low-level

• First generation

• Second generation

High-level

• Third generation

• Fourth generation

​

First generation

​

Machine Code

Directly executable by the processor

The generation that ‘computers understand’

Difficult to program in, hard to understand, hard to find errors (hard to debug)

​

​Wilf

​You know the key features of Machine language.

​Second generation

​Assembly Code

Uses mnemonics

Easier to program but still difficult

One Assembly Language instruction translates to one Machine Code Instruction (1-1 relationship)

Needs to be translated into Machine Code for the computer to be able to execute it

​It is most commonly used to program Device Drivers.

Device Drivers are loaded into memory by the Operating System and used to control the operation of a Hardware Device e.g. Graphics Card Drivers, Printer Drivers.

​Wilf

​You know the key features of Assembly language.

​Wilf

​You know the key features of High language and other languages.

Multiple Choice

Which language translator is needed for the first generation?

• Compiler

• Interpreter

• No Translator

• Language Translator

​Fourth generations

​Known as a Declarative Language

Facts and Rules are stated

Describes what computation should be performed and not how to perform it

Examples include:

SQL

Expert Systems

Artificial Intelligence

​

Multiple Choice

Identify the language this code belongs to?

Dim Num1, Num2, Tot as Integer

Num1 = Console.Readline()

Num2 = Console.Readline()

Tot = Num1 + Num2

Console.Writelein(“Total is: “ & Tot)

• High-level (3rd Generation)

• Low-level (2nd Generation)

• Low-level

  (1st Generation – Machine Code)

​Third Generation

​Easier to understand (programmer)

Easier to find errors, easier to de-bug

Uses English-Like Keywords

One instruction translates into many machine code instructions

e.g.’s Java, Basic, Pascal, C+

​Translated using:

Compiler

Interpreter

Multiple Choice

Identify the language this code belongs to?

01010101010100101010100101010101010011111001000100001010100101

• High-level (3rd Generation)

• Low-level (2nd Generation)

• Low-level

  (1st Generation – Machine Code)

Multiple Choice

Identify the language this code belongs to?

LOAD r1, c

LOAD r2, d

ADD r1, r2

DIV r1, #2

• High-level (3rd Generation)

• Low-level (2nd Generation)

• Low-level

  (1st Generation – Machine Code)

Multiple Choice

Identify the language that has this feature. 

Directly executable by CPU

• Assembly language

• Machine code

• High level langauge

Multiple Choice

Identify the language that has this feature. 

1-1 relationship between --------- Instruction and Machine Code

• Assembly language

• Machine code

• High level langauge

Multiple Choice

Identify the language that has this feature. 

Easier for programmer to understand,

de-bug and write

• Assembly language

• Machine code

• High level langauge

Multiple Choice

Identify the language that has this feature. 

1 to Many relationship in instructions with machine code.

• Assembly language

• Machine code

• High level langauge

Multiple Choice

Identify the language that has this feature. 

- Hard to understand

- Hard to De-Bug

• Assembly language

• Machine code

• High level langauge

​Walt

​To be able to describe the differences in operation between a Compiler and Interpreter

​

​Language translators

​Language Translators are used to translate a language into a form that the will be able to directly execute

Compilers/Interpreters are used for 3rd Generation

​

​

​Interpreters

Translate and execute source code.

Line by line, statement by statement.

Source code is checked for syntax – if correct, code is executed.

If incorrect interpreting is stopped.

Used for development (aid debugging).

​

​​Compilers

Translate entire source code all in one go into Machine Code.

Optimise code.

Used at the end of development (ready for shipping).

Error Reports created along with Object Code.

​

Multiple Choice

Translation software needed at run-time

• Language Translator

• Compiler

• Interpreter

Multiple Choice

Translation software needed at run-time

• Language Translator

• Compiler

• Interpreter

Multiple Choice

Translates entire source code in one go

• Language Translator

• Compiler

• Interpreter

Multiple Choice

Which translator converts from different languages?

• Language Translator

• Compiler

• Interpreter

Multiple Choice

Which translator is used at the end of development?

• Language Translator

• Compiler

• Interpreter

Multiple Choice

Which language translator is used during the development of a program?

• Code Translation

• Compiler

• Interpreter

Multiple Choice

Which language translator is used during the development of a program?

• Code Translation

• Compiler

• Interpreter

Multiple Choice

Which language translator produces Object Code and an Error Report?

• Code Translation

• Compiler

• Interpreter

Multiple Choice

Which language translator does not convert source code into machine code?

• Code Translation

• Compiler

• Interpreter

Multiple Choice

Which language translator does not convert source code into machine code?

• Code Translation

• Compiler

• Interpreter

Multiple Choice

What is meant by source code?

• The final executable program

• The code written by the programmer

• The additional information about errors

• Code relating to sources of information on the Internet

​Walt

​To be able to describe the common tools and facilities in an Integrated Development Environment (IDE).

​

​Integrated Development Environment (IDE):

​Editor (for writing the code)

Error Diagnostics (such as de-bug facilities)

Run-Time Environment

Translators

​