In this blog post, we explore why programming languages are needed to communicate with computers and what roles compilers and interpreters each fulfill.
Beginners learning programming often expect computers to handle everything automatically. But when they actually start writing programs, they realize the joke “computers are lazy and dumb” is no exaggeration. Computers will never perform tasks unless explicitly instructed by the user. Even when instructed, they won’t function properly unless commands are delivered according to strict rules and sequences. Furthermore, computers cannot understand the languages humans use daily; they can only interpret machine code composed solely of 0s and 1s. Because of these characteristics, a ‘programming language’ is absolutely necessary to communicate with computers.
Programming languages serve as an intermediary tool enabling mutual understanding between computers and humans. To convert this into machine language that computers can recognize, a program called a compiler is required. Since compilers convert the code written by programmers into machine language all at once, problems arise if the code is not written perfectly, preventing execution. A single typo or logical error can cause the entire program to fail. This can be frustrating for many programmers and reduces development efficiency.
To solve this problem, interpreters were developed. Unlike compilers, interpreters don’t convert the entire code at once. Instead, they interpret each line sequentially, converting it into a language the computer can understand. This is similar to how a parent reads a book to a young child, explaining each sentence one by one. If the child doesn’t understand a difficult word, the parent explains it simply and moves on, allowing the child to gradually grasp the sentence. An interpreter plays this parental role, interpreting each line of code sequentially and converting it into a form the computer can understand.
First, the interpreter must teach the computer some basic functions. For example, it explains fundamental operations or commands like “DEF(x, y) is a function that stores the value of y in x.” This is akin to teaching a young child simple words. Subsequently, it operates by receiving the programmer’s code line by line and interpreting it by combining predefined functions. For instance, if a programmer inputs the command “x = 2 + 3,” the interpreter converts this code into a format like “DEF(x, SUM(2, 3))” before passing it to the computer. This enables the computer to understand and execute the command. This approach allows programmers to write code as if conversing with the computer. If an error is found in the code, it can be corrected immediately and re-executed.
One advantage of interpreters is that the process of writing and modifying code is faster and more flexible compared to compilers. Compilers must convert the entire code at once, meaning even a small error can halt the entire program’s execution. Interpreters, however, execute line by line, so if an error occurs, only that specific line needs to be corrected and re-executed. This is particularly advantageous for educational purposes or prototype development, helping beginners easily access computer programming. This is because you can test the code line by line to see how it works, without needing to write the entire program perfectly from start to finish.
However, the interpreter approach can be somewhat inefficient once the code is complete. Since the code must be reinterpreted and converted into functions for each execution, it can slow down execution speed. For this reason, compilers are generally used for large-scale programs or when optimization is critical. Nevertheless, interpreters still offer significant advantages when a simple development environment is needed or for learning purposes.
In conclusion, interpreters, as tools facilitating communication between computers and programmers, are crucial technologies that enhance programming accessibility. Understanding the distinct characteristics of both compilers and interpreters and selecting the appropriate one for the situation can make programming work more efficient and flexible. It is hoped that programming beginners will experience the joy of conveying commands to computers using interpreters and gradually develop their ability to communicate with computers.
