What is the function of an interpreter in programming?

An interpreter serves a crucial role in programming by translating and executing high-level language code on-the-fly, statement by statement, during runtime. This allows developers to write code and test it interactively, which can enhance the debugging process and facilitate rapid prototyping.

When an interpreter processes a program, it reads each line or statement, converts it into a lower-level format, and immediately executes it. This direct execution avoids the need for a separate compilation step, making it particularly useful for scripting languages and environments where quick iterations and adjustments are common.

In contrast, other options describe different processes related to program execution. Some involve compiling entire programs before execution, which is characteristic of compilers rather than interpreters, while others pertain to code optimization, which generally occurs in the compilation phase rather than during execution. Thus, the choice highlighting the interpreter's ability to translate and execute code at runtime captures the essential function of this tool in programming languages.