Interpreter

Introduction to Interpreter

  • An interpreter is a type of program used to execute other programs.
  • It translates source code into machine code, line by line, at the time the program is run.
  • Unlike compilers, interpreters do not produce a separate machine code file, but rather execute code directly.
  • They are used for scripting and some high-level languages such as Python and PHP.

How Interpreter Works

  • The interpreter reads a program’s code one line at a time.
  • It translates the source code line into an intermediate representation or directly into machine code.
  • Once the line is translated, it is immediately executed.

Advantages of Interpreters

  • Interpreters are generally more flexible than compilers as they can execute code interactively.
  • Changes in the source program can be tested immediately as no recompiling and linking is necessary.
  • They are better for dynamic languages, as they can handle changing conditions at runtime with ease.

Disadvantages of Interpreters

  • Programs run by an interpreter generally run more slowly than those run by a compiler as each line must be translated each time it is executed.
  • As the source code is needed at runtime, the entire program must be present, which can pose security issues.

Differences between Interpreter and Compiler

  • The main difference between a compiler and an interpreter is when and how they translate the source code into machine code.
  • A compiler translates the whole program before execution.
  • An interpreter translates one line at a time during execution.

Examples of Interpreted Languages

  • Examples of languages typically run through an interpreter include Python, Ruby, PHP, and JavaScript.
  • Such languages are often used for web development, data analysis, and scripting tasks.

Key Terms

  • Interpreter: A program that translates and executes each line of source code one at a time.
  • Source Code: The original form of a program in a high-level language that can be read and modified by a programmer.
  • Machine Code: Low-level code that can be executed directly by the computer’s processor.
  • Dynamic Languages: In the context of interpreted languages, these are languages that allow variable declarations or modifications at runtime.
  • Compile: The process of translating high-level source code into machine code that can be executed by a computer.