Home/ Questions/Q 4076394
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-20T17:25:10+00:00

I know regular expressions are very powerful, and to become an expert with them

  • 0

I know regular expressions are very powerful, and to become an expert with them is not easy.

One of my colleagues once wrote a java class to parse formatted text files. Unfortunately it caused a StackOverFlowError in the first integration test. It seems difficault to find the bug, before another colleague from structural programming world came over and fixed it quickly by thowing away all regular expressions and instead using many nested conditional statements and many split and trim methods, and it works very well!

Well, why do we need regular expression in a programming language like Java? As far as I know, the only necessary usage of regular expression is the find/replace function in text editors.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Anything that can be expressed as a regular expression can, by definition, be expressed as a chain of IFs. You use REGEX basically for two reasons:

    • REGEX libraries tends to have optimized implementation that most of the time will be better than a hand-coded “IF” chain for some expressions.
    • REGEX are usually easier to follow, if properly written, than the IF chains. Specially for more complex expressions.

    If your expression gets too complex, the use the advice given by this answer. If it get truly nasty, think about learning how to use a parser generator like ANTLR or JavaCC. A simple grammar usually can replace a regex, and it is a lot easier to maintain.

    • 0