rspec/rules/S4635/description.adoc

Looking for a given substring starting from a specified offset can be achieved by such code: ``str.substring(beginIndex).indexOf(char1)``. This works well, but it creates a new ``String`` for each call to the ``substring`` method. When this is done in a loop, a lot of ``Strings`` are created for nothing, which can lead to performance problems if ``str`` is large.

To avoid performance problems, ``String.substring(beginIndex)`` should not be chained with the following methods:

* ``indexOf(int ch)``
* ``indexOf(String str)``
* ``lastIndexOf(int ch)``
* ``lastIndexOf(String str)``
* ``startsWith(String prefix)``

For each of these methods, another method with an additional parameter is available to specify an offset.
Using these methods gives the same result while avoiding the creation of additional ``String`` instances.