Question

What does [1] at the end of statement mean?

String magnitudeString = details.split(" ")[1];

Can’t it be written like this:

String [] magnitudeString = details.split(" ");

Answer 1

[1] is indexing an array: the result of String.split() is an array, and [1] is taking the second element from that result.

This is equivalent to:

String strs[] = details.split(" ");
String magnitudeString = strs[1];

So it can’t be re-written quite like your suggestion.

Obviously either of these is a problem if the result of split has fewer than 2 elements, so a length check before accessing array elements is prudent, and the immediate form won’t allow this.