Question

Is there an easy way to trim a String based on his Offset and Count values, that is, a function that returns OO for a String FOOBAR with an offset of 1 and a count of 2?

Obvious, one could write a simple function for this task, but I wonder if their is not a predefined Java functionality for this?

//edit: To clearify: I do mean the offset and count values defined within the given String, not external Integer values.

Answer 1

EDIT: Okay, now you’ve made your question clearer, it sounds like this is the scenario you’re talking about, and the solution using the String(String) constructor:

// offset = 0, count = 6, backing array = { 'F', 'O', 'O', 'B', 'A', 'R' }
String original = "FOOBAR";

// offset = 1, count = 2, backing array = { 'F', 'O', 'O', 'B', 'A', 'R' }
String substring = original.substring(2);

// offset = 0, count = 2, backing array = { 'O', 'O' }
String trimmed = new String(substring);

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Yup, substring:

String substring = text.substring(offset, offset + count);

substring takes two parameters – the “begin index” (inclusive) and the “end index” (exclusive) – hence the addition in the above code.