Computer programs are usually written in high level languages such as Java, C#, Python etc. High level programming languages consist of phrases and words from prevalent human languages like English. High level languages are used to make the source code of any given computer program. However, even though high level languages are easier to learn and understand for humans, computers can’t understand it. They can only function if the instructions are provided to them in machine language. i.e., a program in 0s and 1s (binary form).

In order for a computer to understand and function based on instructions composed in high level languages, we need to convert it into machine language. In order to do this, a compiler or an interpreter is used to transform the source code into machine language. Compilers and interpreters are software programs that are used for converting computer programs in high-level languages into machine language (0s and 1s binary form). This allows the computer to understand the command and perform the required tasks. While both interpreters and compilers perform similar tasks, there are distinct differences in the way they operate. In this post, we will find out about all of them. Let’s get started.

Interpreter vs Compiler: All You Need to Know

What is an Interpreter?

An interpreter is a software program that translates a source code into a machine language. An interpreter accomplishes this task by reading the high level language source code line-by-line while interpreting and running the program.

Interpreter: Pros and Cons

Interpreters are easier to work with the source code. Hence, they are better for beginners. However, interpreted programs are a little limited because they can only run on those computers which have the same interpreter.

What is a Compiler?

A compiler is a software program that follows the syntax rule of a programming language and converts the high level language source code into a machine language code which can be understood by the computer. If there is some error in the source code, the compiler won’t be able to fix it and it will just generate an error message which will ask you to fix the error within your source code. If your original source code is error free, the compiler will convert it into machine code. A compiler converts the entire source code into machine code together and executes your program.

Phases of the compilation process

Analysis Phase

This compiler phase is widely referred to as the front end phase in which a source code is split into fundamental parts to check grammar, syntax, and semantics of code. Once that process is concluded, an intermediate code is produced. Three types of analyzers are used during the analysis phase of the compilation process: lexical analyzer, semantic analyzer, and syntax analyzer.

Synthesis Phase

The Synthesis phase is widely referred to as the back end phase in which the intermediate code (which was generated in Analysis Phase) is optimized and generated into target machine code. Code optimizer and code generator tasks constitute the synthesis phase of the compilation process.

Compiler: Pros and Cons

When you use a compiler to translate a source code into machine code, the program codes are translated into specific object codes. This significantly reduces the time of code execution. However, the big drawback of using a compiler is the fact that in order to make changes to your program, you always have to go back to your source code.

Interpreter vs Compiler: Conclusion

Differences	Compiler	Interpreter
Programming Steps	Write a program in source code.Compiler analyzes your program statements and checks for mistakes. If an error is found in a program, an error message is displayed.If the program is error free, the compiler converts the high level language source code program into machine language code.The compiler links all the code files into a single runnable program. This is referred to as an “exe” file.Then the program is run and the task is executed.	Write a program in source code.Files aren’t linked and separate codes aren’t generated.The source code programming statements are executed line-by-line. If the interpreter encounters an error in a specific statement, execution is halted till the error is removed.
Translation type	A compiler translates complete high-level programming code into machine code at once.	An interpreter translates the high level language source code into machine language code, one statement at a time.
Advantage	Since the entire source code is converted to machine code, the execution is faster.	As the source code is interpreted line-by-line, it’s easier to detect errors and fix them.
Disadvantage	If you want to make any change to the program, you will have to access the source code.	Interpreted programs are restricted to computers which are equipped with the same interpreter.
Machine code	The converted source code is stored as machine code on the disk.	The machine code is never stored on the disk.
Running time	A compiler takes a long time to analyze source code. However, overall compiled programming code runs faster than that with an interpreter.	An interpreter takes less time to analyze source code as compared to a compiler. However, as the code is interpreted statement by statement, it takes longer to execute the program.
Program generation	The compiler generates an output of a program (in the form of an exe file) which has the ability to run independent of the source code.	The interpreter doesn’t generate a separate machine code as an output program. So it has to check the source code during each step of execution.
Execution	The process of program execution takes place separately from its compilation process. Hence the entire source code has to be compiled and converted into machine code before the program can be executed.	The process of program execution is a part of interpretation steps. Hence it is executed line by line.
Memory requirement	A compiled program is generated into an intermediate object code, which requires further linking. This needs more memory from the system.	An interpreted program does not generate an intermediate code. Hence there is no need for any kind of extra memory.
Best suited for	C and C++ are the most popular programming languages based on the compilation model.	JavaScript, Python, Ruby are based on the interpreter model.
Error execution	A compiler will display all the error messages during the compilation stage of the program. So you can’t run the program without fixing program errors. Hence the debugging process is a little more complex while using a compiler.	An interpreter reads the program line-by-line and displays an error if it’s present in a line. You will need to correct the error to interpret the next line of the program. This makes debugging significantly easier while using an interpreter.

So that was our brief guide to the differences between Interpreters and Compilers. Hopefully you have a better idea on the subject and will be able to choose the right tool for your programming needs.