Comparative Notes: Compiler vs. Interpreter
August 18, 2025
Definition & Working Principle -
Compiler: Translates the entire source code of a high-level language into machine code (object code) in one go before execution. The resulting code can then be run multiple times without recompiling.
Interpreter: Translates and executes code line-by-line or statement-by-statement. No separate machine code file is produced; the source code is always required for execution.
Program Scanning & Translation -
Compiler: Scans the whole program at once, checking for errors collectively after the full scan.
Interpreter: Scans and executes each line individually, reporting errors line-by-line as they are encountered.
Compiler: Reports all errors after attempting to compile the entire code, making error correction slightly more complex.
Interpreter: Easily detects and reports errors at each statement, allowing for immediate correction and easier debugging.
Output & Execution -
Compiler: Produces an independent executable file (machine code) that can be run any time without the original source code.
Interpreter: Does not produce an executable file; must re-interpret the source code every time, leading to slower execution.
Compiler: Program runs faster after initial compilation since translation has already occurred.
Interpreter: Slower program execution as code is translated and run simultaneously, each time the program is executed.
Compiler: Requires more memory initially to store the compiled code.
Interpreter: More memory efficient since it does not produce or use an intermediate code file.
Compiler: Longer cycle; compile-link-execute steps demand time before executable is ready.
Interpreter: Shorter development cycle; suitable for rapid testing, prototyping, and debugging.
Platform Dependency -
Compiler: Compiled code is platform-specific; separate compilation needed for each platform.
Interpreter: Interpreted code is portable if an appropriate interpreter exists on the target platform
Use Cases & Examples -
Compiler: Used in performance-critical applications. Examples: C, C++, Rust, and Swift.
Interpreter: Used for scripting, rapid development, and education. Examples: Python, Ruby, JavaScript, Perl, MATLAB.
Debugging -
Compiler: Debugging is less interactive due to delayed error reporting.
Interpreter: More interactive debugging as errors halt execution at the exact statement.
Size & Flexibility -
Compiler: Larger in size, less flexible.
Interpreter: Smaller in size, more flexible for dynamic code execution.
