Chapter 5 (Section 2) #2

Question 1

Section 1: Fundamental Concepts of Translation

Question 2

Why must programs be translated into machine code before execution?

Answer 2

CPU hardware can only process instructions in machine code (binary) because its made up of logic gates. Therefore, any program written in a high-level or assembly language must be converted into machine code and loaded into main memory to run.

Question 3

What is the definition of a Translator?

Answer 3

Systems software that converts a source program written in a language other than machine code into a format that the computer can execute.

Question 4

What is a Source Program?

Answer 4

The original program written by the programmer in a high-level or assembly language before it has been translated.

Question 5

What is an Object Program (Object Code)?

Answer 5

The machine code version of a program that is produced after the source code has been processed by a compiler or assembler.

Question 6

How does the mapping of instructions differ between low-level and high-level languages?

Answer 6

Low-level language instructions generally have a one-to-one mapping with machine code, whereas one high-level language instruction usually translates into multiple machine code instructions.

Question 7

What is the definition of machine independent?

Answer 7

The program code can be translated to run on any processor / platform

Question 8

Section 2: Types of Translators

Question 9

What is an Assembler?

Answer 9

A program that translates a source program written in a low-level assembly language into machine code.

Question 10

What is a Compiler?

Answer 10

A program that translates a source program written in a high-level language into machine code or p-code (object code) as a single, complete unit.

Question 11

What is an Interpreter?

Answer 11

A program that analyzes and executes a high-level language program line by line without producing a separate object code file.

Question 12

What is bytecode?

Answer 12

It is partially complied code that is generated using a compiler. This bytecode can only be interperted on a virtual machine and is machine independent.

Question 13

Describe how Java source code is translated.

Answer 13

1. Java uses a two-step translation process.
2. Java code is partially compiled.
3. Code is translated first into intermediate code (bytecode) using the Java compiler.
4. The bytecode is finally interpreted by the Java Virtual Machine.

Question 14

Section 3: Performance and Resource Management

Question 15

How does execution speed compare between compiled and interpreted programs?

Answer 15

Compiled programs run faster because the translation is performed once before execution; interpreted programs run slower as each line must be translated every time the program is executed.

Question 16

How do compilers and interpreters differ in their use of memory during execution?

Answer 16

A compiled program only requires the object code to be in memory. An interpreted program requires both the source code and the interpreter software to be present in memory during execution.

Question 17

Which translator is more efficient for programs that use loops?

Answer 17

A compiler, because it translates the loop code once. An interpreter must re-translate every instruction inside the loop for every iteration.

Question 18

Section 4: Development and Security

Question 19

Why is an interpreter often preferred during the initial development phase of a program?

Answer 19

It allows for faster testing and debugging because the programmer can see the results of changes immediately without waiting for a lengthy compilation of the entire project.

Question 20

How do compilers and interpreters handle error reporting differently?

Answer 20

A compiler scans the entire program and provides a complete list of all syntax errors at the end. An interpreter stops execution the moment it encounters a single error.

Question 21

Why is a compiler better for protecting Intellectual Property (IP)?

Answer 21

A compiler produces an object code file that is difficult for humans to read or reverse-engineer, allowing the developer to distribute the software without sharing the original, readable source code.

Question 22

How does portability differ between compiled and interpreted code?

Answer 22

Compiled object code is often specific to a particular hardware architecture. Interpreted source code can run on any machine as long as a compatible interpreter is installed on that system.

Question 23

Section 5: Errors and Debugging

Question 24

What is a Syntax Error?

Answer 24

An error in the grammar or rules of the source program (e.g., a misspelled keyword or missing punctuation) that prevents translation.

Question 25

What is a Logic Error?

Answer 25

An error in the design or logic of a program that causes it to produce incorrect results even though the program runs without crashing.

Question 26

What is the definition of Debugging?

Answer 26

The process of finding and correcting logic errors in a program by tracing its execution.

Question 27

Section 6: Integrated Development Environments (IDE)

Question 28

What is an Integrated Development Environment (IDE)?

Answer 28

A software suite that provides a comprehensive set of programs and tools (such as editors and debuggers) used by programmers to write, test, and translate high-level language programs.

Question 29

What is the purpose of the Source Code Editor in an IDE?

Answer 29

It provides a workspace for writing and modifying code, often featuring tools specifically designed to make the code easier to manage.

Question 30

What is "Prettyprinting" in an IDE?

Answer 30

A feature that automatically formats source code with consistent indentation and color-coding to make it easier for humans to read and understand.

Question 31

What is Context-sensitive Prompting?

Answer 31

A feature that displays predictions or suggestions for the code being entered (like variable names or keywords) based on the current context.

Question 32

What is Dynamic Syntax Checking?

Answer 32

An IDE feature that underlines or highlights statements that violate the rules of the programming language while the programmer is still typing.

Question 33

What is Bracket Matching?

Answer 33

A feature that highlights the corresponding opening or closing bracket when the cursor is placed on one of them, helping to manage nested structures.

Question 34

What are Collapsible Code Blocks?

Answer 34

A feature that allows the programmer to hide or "collapse" sections of code (like functions or loops) to make navigating large programs easier.

Question 35

Section 7: Runtime and Debugging Tools

Question 36

What is a Run-time Environment?

Answer 36

A component of an IDE that allows a program to be executed and tested while providing access to specialized debugging tools.

Question 37

What is a Breakpoint?

Answer 37

A deliberate pause placed at a specific line of code by the programmer to stop execution so that the current state of the program can be inspected.

Question 38

What is Single Stepping?

Answer 38

A debugging technique where the program is executed one line at a time, allowing the programmer to observe the effect of each instruction.

Question 39

What is a Report Window?

Answer 39

A separate window in the IDE's debugging environment that displays the current contents of variables and data structures as the program runs.

Question 40

What is an Auto-Documenter?

Answer 40

A feature that automatically generates documentation for the functions, variables, and overall purpose of the code based on the source files.

Question 41

Section 8: Classified Questions

Question 42

Describe the benefits of using a compiler to translate high-level code.

Answer 42

1. Once translated the compiler software is not needed to run the program. 2. Compiled code should execute faster. 3. Compiler produces an executable file. 4. The executable file produced by a compiler can be distributed without users having sight of the source code.

Question 43

Describe the benefits of using an interperter to translate high-level code.

Answer 43

1. Easier de-bugging. 2. The interpreter stops when error encountered, so errors can be corrected in real time. 3. The interpreter translates a statement then executes it immediately. 4. Parts of the program can be tested, without all the program code being available.

Question 44

Identify features that support the visual presentation of the code in a typical Integrated Development Environment (IDE)

Answer 44

1. Prettyprinting. 2. Expand/collapse code blocks. 3. Auto indentation / formatting.

Question 45

Identify features that support the debugging of the code in a typical Integrated Development Environment (IDE)

Answer 45

1. Single stepping. 2. Breakpoints. 3. Report window. 4. Variable expressions.

Question 46

Describe some differences between a compiler and an interperter.

Answer 46

1. Compiler creates an executable//an interpreter does not create an executable. 2. The compiled program can be independently distributed. 3. Compiler reports all errors at the end of compilation//an interpreter stops when it reaches an error. 4. Interpreter executes each statement immediately after decoding/checking it. 5. The compiled program does not require compiler/source code to be present.

Question 47

Explain why software is often developed using library files.

Answer 47

1. The code is already written so the programmer is not starting over again which saves time. 2. The code will have been used by many people so it should be already thoroughly tested and relatively error-free / won’t need re-testing. 3. The programmer can use e.g. mathematical / graphics functions that he may not know how to code. 3. Use of named library functions can simplify the program and make it easier to read. 4. The library routine code should conform to industry standards and therefore contribute towards a more robust program.