Both are language translators that convert programs written in High-Level Language (HLL) (like C, Java, Python) into Machine Language (Binary), so that the computer can understand and execute them.
1. Compiler
- Definition: A compiler translates the entire program (source code) into machine code at once.
- After compilation, an object code (executable file) is generated.
Features of Compiler
- Translates the full program before execution.
- Errors are displayed after complete compilation.
- Execution is faster (because translation is done once).
- Example Languages: C, C++, Java (partly).
Advantages
- Fast execution.
- Object code can be saved and reused without recompilation.
Disadvantages
- Error detection is difficult (errors are shown only after compilation).
- Requires more memory.
2. Interpreter
- Definition: An interpreter translates and executes the program line by line.
- No separate object code is generated.
Features of Interpreter
- Reads one statement, translates it, and executes immediately.
- Errors are shown immediately (line by line).
- Execution is slower (because translation happens every time).
- Example Languages: Python, JavaScript, Ruby, BASIC.
Advantages
- Easier for beginners (errors are detected instantly).
- Uses less memory (no object code storage).
Disadvantages
- Slow execution speed.
- Program must be translated every time before running.
Comparison Table: Compiler vs Interpreter
| Feature | Compiler | Interpreter |
|---|---|---|
| Translation Method | Entire program at once | Line by line |
| Speed | Faster execution | Slower execution |
| Error Detection | Errors shown after compilation | Errors shown immediately |
| Output | Creates object code (executable) | No object code (direct execution) |
| Examples (Languages) | C, C++ | Python, JavaScript, BASIC |
✅ Summary for Exams
- Compiler → Translates whole program at once → Faster execution but delayed error detection.
- Interpreter → Translates line by line → Slower execution but immediate error detection.