import java.util.*;
 
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String text = "\u00A0 \u00A0\tStart reading\u00A0here...";
		System.out.println("Text: '" + text + "'");
		System.out.println(text.replaceAll("(?U)\\s+", "")); // removes all whitespaces
		System.out.println(text.replaceAll("(?U)\\s", "-")); // replaces each single whitespace with -
		System.out.println(text.replaceAll("(?U)\\s+", "-")); // replaces chunks of one or more consecutive whitespaces with a single -
		System.out.println(text.replaceAll("(?U)\\G\\s", "-")); // replaces each single whitespace at the start of string with -
	}
}

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