Interpreter vs. Compiler

Photo by Blake Connally on Unplash

Introduction

Developers usually build apps by writing code in a high-level language that is only understandable by humans. Meanwhile, the computer has its own language so before a computer program can be executed, human code needs to be converted to computer-readable machine code, and here comes the appearance of interpreters and compilers.

Interpreters and compilers are both translators but they work in very different ways.

Interpreter

The interpreter translates and then executes the code immediately line by line. Therefore, we always need an interpreter on standby while the program runs.

Figure 1: How the interpreter works

Figure 1 shows the interpreter taking a single line of code and translating this into immediate code before executing. It then gets the next line and repeats the process until the end of the source code.

Compiler

In contrast, the compiler takes the whole source code, translates then saves it as an executable file. Since then, the compiler leaves us there and the program can be executed on demand.

Figure 2: How the compiler works

Figure 2 shows the translation process taken by the compiler happens once. Besides, it does not include the code execution part since the compiler does not involve in this process.

Interpreter vs. Compiler

The table below shows the differences in brief between these translators: