If you’ve ever wondered how a computer can understand and execute programs in a language that only humans can understand, then it’s time to learn what a compiler and interpreter are. Welcome to the fascinating world of programming! In this article, we’ll take a look at one of the key tools of a programmer – what a compiler is, how it works, what types there are, and where they are used. And most importantly, what is the difference between a compiler and an interpreter.
Compilers are programs that convert the source code of a program into machine code that is understandable to a computer. Among these types are vectorizing, flexible, dialog, incremental, interpreting, debugging, resident, self-compiling, and universal.
In addition, they can be divided into two groups:
- those that work with specific programming languages;
- those that serve as program compilation systems. Examples of such compilers are GCC, gnat, clang, xcode, gfortran, Makefile, and CMake.
Interpreters, on the other hand, are programs that perform interpretation, i.e., reading and executing program code, without first compiling it into a machine language.
There are two types:
- The simple type executes commands instantly, but can detect errors only at runtime;
- The second type, compiled, uses a compiler to translate the source code into intermediate code and then interprets it. This type is faster, but requires more resources and correct source code.
Some of these translators can work in dialog or read-everything-print loop (REPL) mode. In this mode, the interpreter reads a complete language construct, executes it, and outputs the results.
The main differences
When you need to write a program, you should use a compiler or an interpreter. Both of these tools are needed to translate a programming language into one that a computer can understand. Although both tools perform the same task, they do it in different ways. The main difference between them is how they process the source code of the program. A compiler converts all the code into machine language, while an interpreter executes the code line by line.
- The interpreter executes one instruction at a time, translating and executing it, and then moving on to the next. The compiler, on the other hand, translates the entire program at once and then executes it;
- The compiler generates an error report after the entire program has been translated, while the interpreter stops translating after the first error is found;
- A compiler takes more time to analyze and process a high-level language than an interpreter;
- The code execution time of a compiler is faster than that of an interpreter, not only because of the analysis and processing time, but also because the program is already compiled into machine language.