4.2.3 - 4.2.4 | THE COMPLIER AND INTERPRETER

Topics from the Cambridge IGCSE (9-1) Computer Science 0984 syllabus 2023 - 2025

OBJECTIVES
4.2.3 Describe the operation of a compiler and an interpreter, including how high-level language is translated by each and how errors are reported

• A compiler translates the whole code at once before executing it, producing an executable file
• An interpreter translates and executes the code line-by-line
• A compiler provides an error report for the whole code if errors are detected
• An interpreter stops execution when an error is found

4.2.4 Explain the advantages and disadvantages of a compiler and an interpreter

• ​To include an understanding that an interpreter is mostly used when developing a program and a compiler is used to translate the final program

ALSO IN THIS TOPIC
4.1.1 TYPES OF SOFTWARE AND INTERRUPTS
 4.1.2 TYPES OF SOFTWARE AND INTERRUPTS
4.1.3 TYPES OF SOFTWARE AND INTERRUPTS
 4.1.4 TYPES OF SOFTWARE AND INTERRUPTS
4.2.1 TYPES OF PROGRAMMING LANGUAGES
 ​4.2.2 TYPES OF PROGRAMMING LANGUAGES
 YOU ARE HERE | 4.2.3 - 4.2.4 TYPES OF PROGRAMMING LANGUAGES
4.2.5 TYPES OF PROGRAMMING LANGUAGES
SOFTWARE REVISION CARDS
TOPIC 4 KEY TERMINOLOGY
TOPIC 4 ANSWERS
TOPIC 4 TEACHER RESOURCES

TRANSLATORS

​Translators convert High level languages into machine code. When you code a Complier or Interpreter will translate your code. Another type of translator is an Assembler.

COMPLIER

​A compiler is a program that translates source code written in a high-level programming language into machine code (binary code) that can be executed by a computer. The compiler checks the source code for errors and then generates an executable file that can run on the target system. It performs tasks such as syntax checking, code optimization, and memory management. Compilers play a critical role in software development by allowing developers to write high-level code that is easy to read and maintain, while still executing efficiently on the target system.

Some key features of compilers include

• Abstraction: Compilers allow programmers to write code in a high-level programming language, which is closer to human language and more abstract than machine code. This abstraction makes the code easier to read, write, and understand, which speeds up the development process.
• Portability: High-level programming languages are platform-agnostic, which means that code written in one language can be compiled for multiple platforms or operating systems. This makes the code more portable and reduces the need for platform-specific modifications.
• Performance: Compilers translate high-level code into machine code, which can be executed by the computer's central processing unit (CPU) with maximum efficiency. This optimized code provides better performance compared to code written in an interpreted language.
• Debugging: Compilers can detect and report errors in the code during the development stage, making it easier for the programmer to identify and fix bugs.

Advantages of a compiler:

• Performance: Compilers generate optimized machine code that is executed by the computer's central processing unit (CPU) with maximum efficiency. This results in better performance compared to code written in an interpreted language.
• Portability: Compilers can translate high-level code into machine code for multiple platforms or operating systems, making the code more portable.
• Debugging: Compilers can detect and report errors in the code during the development stage, making it easier for the programmer to identify and fix bugs.
• Security: Compiled code is harder to reverse-engineer or modify, providing better security compared to interpreted code.

Disadvantages of a compiler:

• Compilation time: Compilation can take a long time, especially for large projects, which can slow down the development process.
• Complexity: Compilers can be complex and difficult to use, especially for novice programmers.
• Inefficiency: Compilers can generate machine code that is less efficient than hand-written assembly code.
• Inflexibility: Compilers do not allow for immediate feedback and testing during the development process, as the code must be compiled and executed before any errors can be detected.

In summary, compilers offer performance, portability, debugging, and security advantages, but can also have drawbacks in terms of compilation time, complexity, inefficiency, and inflexibility. The choice between using a compiler or an interpreter will depend on the specific requirements of the project and the needs of the programmer.

INTERPRETER

​An interpreter is a program that executes instructions written in a high-level programming language, one line at a time, rather than compiling the code into machine code before execution. Unlike compilers, interpreters don't generate an executable file, they directly execute the code. Interpreters can be used to test code snippets quickly and easily, or to run code on systems where compiling is not possible or practical. However, interpreted code generally runs slower than code that has been compiled, since the interpreter must parse and execute the code every time it is run. Overall, interpreters provide a more flexible and interactive development environment, but have a performance trade-off compared to compilers.

Some key features of interpreters include

• Flexibility: Interpreters allow for immediate feedback and testing during the development process. Programs written in interpreted languages can be executed directly without the need for a separate compilation step. This makes it easier for the programmer to quickly test and make changes to the code.
• Dynamic Typing: Interpreters support dynamic typing, where the type of a variable can be determined at runtime. This makes it easier to write code quickly without worrying about type definitions and allows for greater flexibility.
• Scripting: Interpreters are commonly used for scripting, where small, frequently executed programs are used to automate tasks and make use of existing libraries. Interpreters provide an easy and quick way to run scripts, making them ideal for this use case.
• Portability: Interpreters are platform-agnostic and can be used on multiple operating systems. This makes it easy to develop code on one platform and run it on another, without the need for recompilation.
• Debugging: Interpreters provide detailed error messages during runtime, making it easier for the programmer to identify and fix bugs.

Advantages of an interpreter:

• Flexibility: Interpreters allow for immediate feedback and testing during the development process. Programs written in interpreted languages can be executed directly without the need for a separate compilation step.
• Dynamic Typing: Interpreters support dynamic typing, where the type of a variable can be determined at runtime. This makes it easier to write code quickly without worrying about type definitions and allows for greater flexibility.
• Scripting: Interpreters are commonly used for scripting, where small, frequently executed programs are used to automate tasks and make use of existing libraries. Interpreters provide an easy and quick way to run scripts, making them ideal for this use case.
• Portability: Interpreters are platform-agnostic and can be used on multiple operating systems. This makes it easy to develop code on one platform and run it on another, without the need for recompilation.
• Debugging: Interpreters provide detailed error messages during runtime, making it easier for the programmer to identify and fix bugs.

Disadvantages of an interpreter:

• Performance: Interpreters generate slower code compared to compiled code, as the code must be interpreted at runtime.
• Security: Interpreted code is easier to reverse-engineer or modify compared to compiled code, providing less security.
• Memory usage: Interpreters can consume more memory compared to compiled code, as the interpreter must store the entire program in memory to execute it.
• Portability: Interpreters may not be available for all platforms, and the same code may not run correctly on all platforms without modification.

In summary, interpreters offer flexibility, dynamic typing, scripting capability, portability, and debugging advantages, but can also have drawbacks in terms of performance, security, memory usage, and portability. 

​

1. What is the difference between a compiler and an interpreter?
2. What is an assembly language and how does it relate to low-level languages?
3. Can you explain the purpose of mnemonics in assembly language?
4. What is machine code and how does it differ from high-level code?
5. Why are compilers typically used during the software development stage?
6. What are the advantages and disadvantages of using a compiler?
7. Why are interpreters mostly used in the software development stage?
8. What are the advantages and disadvantages of using an interpreter?
9. Can you explain the difference between dynamic typing and static typing?
10. How does the choice between using a compiler or an interpreter depend on the specific requirements of the project and the needs of the programmer?

ALSO IN THIS TOPIC

4.1.1 TYPES OF SOFTWARE AND INTERRUPTS
4.1.2 TYPES OF SOFTWARE AND INTERRUPTS
4.1.3 TYPES OF SOFTWARE AND INTERRUPTS
4.1.4 TYPES OF SOFTWARE AND INTERRUPTS
4.2.1 TYPES OF PROGRAMMING LANGUAGES
4.2.2 TYPES OF PROGRAMMING LANGUAGES
4.2.3 - 4.2.4 TYPES OF PROGRAMMING LANGUAGES
4.2.5 TYPES OF PROGRAMMING LANGUAGES
SOFTWARE REVISION CARDS
TOPIC 4 KEY TERMINOLOGY
TOPIC 4 ANSWERS
TOPIC 4 TEACHER RESOURCES