Splitting a space separated string

Question

String numbers = \"5 1 5 1\";

So, is it:

String [] splitNumbers = numbers.split();

or:

String [] spli         


        

Answer 1

In your above case split("\s+");, you need to escape \ with another backslash, which is:

split("\\s+");

Or

split(" "); also can do it

Note that split("\\s+"); split any length of whitespace including newline(\n), tab(\t) while split(" "); will split only single space.

For example, when you have string separated with two spaces, say "5   1 5 1" ,

using split("\\s+"); you will get {"5","1","5","1"}

while using split(" "); you will get {"5","","1","5","1"}

Answer 2

You must escape the regex with an additional \ since \ denotes the escape character:

public static void main(String[] args) {
    String numbers = "5 1 5 1";
    String[] tokens = numbers.split("\\s+");
    for(String token:tokens){
        System.out.println(token);
    }
}

So the additional \ escapes the next \ which is then treated as the literal \.

When using \\s+ the String will be split on multiple whitespace characters (space, tab, etc).