How to get 4th last occurence in a string

[loial]

In the following string I want to find the psotion of the next to last
occurrence of "/" so that I can set a variable to "656/8888"


/10000/20000/656/8888


Can lastindexOf do this?

 

[Stefan Rybacki]

In the following string I want to find the psotion of the next to last
occurrence of "/" so that I can set a variable to "656/8888"


/10000/20000/656/8888


Can lastindexOf do this?

Obviously not. It is called LASTindexOf for a reason. So first things first, do
you want to get the 4th or second to last occurrence? If second to last you know
at least one way to do it if you think algoritmic, do you? One hint. What do you
get when you get the last index and then get the last index again on the string
that is bounded by the previous last index?

Stefan

 

[Patricia Shanahan]

Not directly. You could use lastIndexOf on the original
string to find the rightmost slash, and use it again on the
substring that ends just before that slash:

String str = "10000/20000/656/8888";
String tail = null;
int i = str.lastIndexOf('/');
if (i >= 0) {
i = str.substring(0, i).lastIndexOf('/');
if (i >= 0)
tail = str.substring(i + 1);
}

You can simplify this code a little bit because lastIndexOf has an
alternative form that searches backwards from a specified index.

Patricia