When comparing IntelliJ IDEA vs Nirw Search, the Slant community recommends IntelliJ IDEA for most people. In the question“What are the best open source tools for searching source code?” IntelliJ IDEA is ranked 4th while Nirw Search is ranked 8th. The most important reason people chose IntelliJ IDEA is:
Uses a fast indexing technique to provide contextual hints (auto-completion, available object members, import suggestions). On-the-fly code analysis to detect errors and propose refactorization.
Ranked in these QuestionsQuestion Ranking
Pro Fast and smart contextual assistance
Uses a fast indexing technique to provide contextual hints (auto-completion, available object members, import suggestions).
On-the-fly code analysis to detect errors and propose refactorization.
Pro Smart refactorings
IDEA places an emphasis in safe refactoring, offering a variety of features to make this possible for a variety of languages.
These features include safe delete, type migration and replacing method code duplicates.
Pro Lots of plugins
Many plugins are available for almost any task a developer may need to cover. Plugins are developed by Jetbrains themselves or by 3rd parties through the SDK available for writing them.
Pro Android support, JavaEE support, etc
A very complete development environment support.
Pro Stable and robust
IntelliJ IDEA hardly ever crashes or has any issues that plague other Java IDEs like file corruption or slowness.
Pro Intuitive and slick UI
IDEA has a clean, intuitive interface with some customization available (such as the Darcula theme).
Pro Support for many languages
IntelliJ supports many languages besides Java, some of these are: golang, Scala, Clojure, Groovy, Bash, etc...
Pro Free version available
There is a free community edition (open source) and an ultimate edition, which you can compare here.
The ultimate edition is available for free for one year for students but must be registered through an .edu e-mail account.
Pro Clear and detailed documentation
The documentation is exhaustive, easy to navigate, and clearly worded.
Pro Very powerful debugger
With ability to step into a certain part of a large method invocation (Shift+F7), drop frame, executing code snippets, showing method return values, etc.
Pro Many convenient features
These simplify the daily work, e.g. copy/cut a whole line without the need to select it.
Pro Progress Output
By default, display the file being searched.
Pro Optional multi-line support
Pro Color highlight matches
Pro Tab completion
The command-line for refining a search supports auto-completing based on the current output.
Pro Can refine the initial search
Initial search can be refined by typing in other terms (optionally exclude from results too).
Pro Optional regex or literal text searches
While regex is default, sometimes escaping is inconvenient, in these cases you can perform literal searches.
Con Built with closed source components
The version with full features is not opensource. Parts of the code are under apache licence though.
Con Bugs are not solved as often as they should
They are more interested in adding new features or issuing new versions than solving bugs.
Con Slow startup
Con Uses too much RAM
Con Cannot open multiple projects in the same window
Con Lack of plugins
IntelliJ supports a very small amount of plugins. Althrough thesse are 'quality approved', many features are missing and can't be implemented because of that.
Con Standard hotkeys behave differently
Seems like hotkeys assignment in Idea has no logical consistency.
Like «F3» is usually next match, «Ctrl+W» - close tab, etc — they map to some different action by default.
There is a good effort in making the IDE friendly for immigrants from other products: there are options to use hotkeys from Eclipse, and even emacs. But these mappings are very incomplete. And help pages do not take this remapping into account, rather mentioning the standard hotkeys.
So, people coming from other IDEs/editors are doomed to using mouse and context menus (which are rather big and complex).