How do i replace a double line with a single line in a string in Android?

Question

I have a string:

 This is a test sentence 1.
 This is a test sentence 2.
 This is a test sentence 3.

 This is a test sentence 4.

 This is a test sentence 5.

I would like to replace the double line gap with a single line instead. Such as:

 This is a test sentence 1.
 This is a test sentence 2.
 This is a test sentence 3.
 This is a test sentence 4.
 This is a test sentence 5.

However, I do not know how to detect the double line break, "\\n" works when replacing a single line break but i have tried "\\n\\n" in a replace function with no success.

textView.setText(string.replaceAll("\n\n","\n"));

Answer 1

You could use:

str.replaceAll("[\r\n]+", "\n") 

Source: Remove multiple linebreaks

Answer 2

You can use below code, It will replace the double lines to single line.

string = Pattern.compile("[\r\n]+").matcher(string).replaceAll("\n");
textView.setText(string);

or

 string = string.replaceAll("[\r\n]+", "\n");
 textView.setText(string);

Both should give the same result.