This tutorial explains the main differences between Compiler vs Interpreter along with the advantages and working of compilers and interpreters:
Here, the differences between a Compiler and an Interpreter have been illustrated in a tabular manner for better understanding. Towards the end of the article, we shall look at the advantages of a Compiler over an Interpreter. We would also go through the advantages that the Interpreter has over a Compiler.
This article also enlists answers to some of the FAQs related to Compilers and Interpreters. Let us begin by understanding the basic concept first.
Table of Contents:
Compiler And Interpreter: Key Differences
Computer programs are written in human-understandable languages called High-level languages. Some examples of high-level languages are C, Java, C++, etc. These languages use words from the English language and so they are easy for humans to learn and use.
However, instructions given to the computer in any high-level language cannot be understood by the computer directly. This is because the computer understands only the language of 0’s and 1’s (also called binary code).
Thus, the code written in any of the high-level languages needs to be converted to a machine-understandable code for it to be understood by the computer. This machine understandable code is nothing but the language which the computer understands and is called the machine language.
As it would be very difficult for humans to provide instructions in machine language so the programs are written in a High-level language and then converted to machine language. Compilers and Interpreters are computer programs that convert a code written in a high-level language to machine language.
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What Is A Compiler
Compilers are programs that convert a code written in a high-level programming language to a machine language code before executing it. This makes it possible for the computer to understand the instructions that have been given to it via the program code. Once translated, the computer then executes the instructions to generate the desired output.
It should be noted that for the compiler to compile the high-level code to a Machine language code, the code should be free of errors. However, if there is any syntax error in the high-level code then it would remain as such because the compiler cannot identify or fix this error. Thus the compiled code will not be generated in such a case.
Working of Compiler
- A compiler translates a program written in a High-level language into machine-understandable code at once.
- The machine-understandable code is known as the Object code.
- The Object code is a combination of the binary number (0’s & 1’s).
- The program written in any High-level language is also known as the Source program or program written in Source code.
- The same Object code can be executed each time the High-level program needs to be run. There is no need to compile the program every time unless there has been a change in the source code.
- Due to the generation of an intermediate code, compilers require a larger memory.
- Compilers take longer to analyze the source program.
- Considering the overall execution of a program, compilers are usually faster.
- C and C++ are examples of languages where the source program is compiled before execution.
What Is An Interpreter
Interpreters are also programs that convert a code written in a High-level language to a machine language code, however, this conversion takes place while the code is being executed. Thus each line of code is converted to machine language which is then understood by the computer and then finally executed to give us the desired output.
While the interpreter converts the High-level program to machine language code, any error that it encounters in the syntax is displayed for a line of code before moving onto the next line of code.
Working of Interpreter
- The Interpreter translates a program written in a High-level language into machine-understandable code one line at a time during the execution of the program.
- There is no intermediate code generated during the conversion of the program to machine understandable code.
- The High-level language program, also known as the Source program, has to be interpreted each time the program is to be executed.
- As there is no intermediate code generated, interpreters do not require large memory.
- Interpreters need less time analyzing the source program as the whole program is not translated at once to machine code.
- Considering the overall execution of a program, interpreters are usually slow.
- Javascript, PHP, Ruby, and Perl are examples of languages where the source code is interpreted.
Compiler Vs Interpreter
The below table explains the major differences between the two:
| Compiler | Interpreter |
|---|---|
| Translates a High level program to machine language code - all at once. | Translates a High level program code to machine language code - one line of code at a time. |
| An intermediate code is generated and temporarily saved. It is called the Object code. | Each line of code is translated to machine code and executed at the same time. The translated code is not saved. |
| Compiling a program is faster. | Interpreters are slower as compared to compilers |
| The Object code generated can be run instead of translating the source program each time execution is to be done. | The source program needs to be executed each time(translation and execution both would be done) as there is no Object code generated. |
| All errors found are displayed together after the compilation of the program is complete. | As translation and execution happens one line at a time so errors, if any are displayed for each line as it is translated to machine code. |
| Code execution and compilation of the code are two different processes. | Code Execution is a part of the code interpretation process. |
| Code optimization takes place before code execution, making the execution process faster. | As one line of code is interpreted and executed at a time thus there is no code optimization. |
| The Object code generated is temporarily saved on the disk. | The machine language code generated during execution of each line is never saved. |
| A compiler first analyzes a program and reports all the errors found before the program is compiled. | The interpreter analyzes one line at a time and reports the error found and does not proceed to the next line of code until the error is fixed. |
| Debugging a compiled program is relatively difficult as all the errors found are reported together. | Debugging an interpreted program is relatively easy, as one line at a time is executed and the error is reported. |
| Dynamic typing is difficult to implement for complier based languages | Dynamic typing is supported by interpreter based languages. |
| C and C++ are examples of languages where the code written is compiled. | Javascript, PHP, Ruby and Perl are examples of languages where the code written is interpreted. |
Advantages: Interpreter over Compiler
The advantages that an Interpreter has over a Compiler are as below:
- The debugging of an interpreted program is comparatively easy, as a single line of code is translated and executed at a time.
- Errors are reported by the Interpreter for a single line of code at a time, as the translation and execution happen simultaneously.
- Interpreters are memory efficient as no temporary storage of the translated code takes place unlike as in a compiler where the Object code is temporarily stored on the disk.
- The Interpreter analyzes one line at a time and thus needs less time to analyze the source program, however; the Compiler analyzes the complete program in one go and thus needs more time for analyzing.
Advantages: Compiler over Interpreter
The advantages that a Compiler has over an Interpreter are as below:
- As compilers analyze the program before compiling it, this ensures all errors are identified and corrected before the compiled code is generated.
- An intermediate code is also known as the Object code generated which can then be used each time the program is to be run, thus eliminating the need for compiling the source program each time.
- Compiling a program is usually faster than interpreting it.
Frequently Asked Questions
Q #1) What is the difference between compiler vs interpreter?
Answer: Although Compilers and Interpreters perform the same job of translating a High-level program to Machine language yet the difference lies in the way the translation happens. In the case of a Compiler, the entire program is converted to machine code in one go whereas in the case of an Interpreter the translation happens one line of code at a time along which any error(s) found is/are reported simultaneously.
Q #2) Is a compiler or interpreter faster?
Answer: Translation of a code using a Compiler is faster as compared to the translation time taken by the Interpreter for the same piece of code.
Q #3) What are a compiler and its types?
Answer: Compilers are translation programs that convert High-level program code to machine language code so that it can be understood by the computer. Depending on how the translation process takes place, Compilers are of the below types:
- Single Pass Compilers
- Two-Pass Compilers
- Multipass Compilers
Q #4) Is Python a compiler or interpreter?
Answer: Python code is interpreted but before being interpreted the source code is first translated to bytecode which is then executed by the Python interpreter. The Python source is stored as a .py file which is then translated to bytecode and stored as a .pyc or .pyo file extension.
Q #5) What are the three types of translators
Answer: The three types of translators are:
- Compilers
- Interpreters
- Assemblers
Q #6) What are the two types of low-level language?
Answer: The two types of low-level languages are:
- Machine Language
- Assembly language
Q #7) What is the difference between compiler and interpreter and assembler?
Answer:
Compiler: This is a translation program that converts a complete high-level program code to machine code in one go.
Interpreter: This is also a translation program that converts a complete high-level program code to machine code but one line of code at a time.
Assembler: This is a translation program that converts a code written in Assembly language to machine code.
Conclusion
We hope this article helped understand the differences between interpreters and compilers. Through this article, we explained the concept of why Compilers and Interpreters are needed. The article also covered the functions of Compilers and Interpreters.
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For better understanding, we presented the differences between a Compiler vs Interpreter in a tabular manner. The advantages of a Compiler over an Interpreter were also briefly stated. At the same time, we also explained the advantages of an Interpreter over a Compiler.