Java replaceAll("\\s+") vs replaceAll("\\\\s+") [duplicate]

Question

What's the difference between replaceAll("\\s+") and replaceAll("\\\\s+")? Usually I use \\s+ but sometimes I see \\\\s+.

Filagree

\ is written as \\ in Java. This should help you. – Barroom

This should help to solve your problem: #4654331 – Fye

Answer 1

\\s+ --> replaces 1 or more spaces.

\\\\s+ --> replaces the literal \ followed by s one or more times.

Code:

public static void main(String[] args) {
    String s = "\\sbas  def";
    System.out.println(s);
    System.out.println(s.replaceAll("\\s+", ""));
    System.out.println(s.replaceAll("\\\\s+", ""));

}

O/P :

\sbas  def
\sbasdef
 bas  def

Capstone

"...followed by s one or more times." Do u mean symbol "s" or spaces? – Filagree

But where is the first "\" here "\sbasdef"? – Filagree

@MaximGotovchits - the character s not spaces. The first `\` will be escaped. – Capstone

It also removes control characters like new line, tab, etc. Example: " \r \n\n \t ".replaceAll("\\s+","" ).length() == 0 >> true – Cotidal