How the subString() function of String class works

[Harshit Rastogi]

Hi
please see the following code.

  
String s = "Monday";
if(s.subString(0,3).equals("Mon"){}

String s2 = new String(s.subString(0,3));
String s3 = s.subString(0,3);
  

I know that line 3 will still point to "Monday" and have a new String object with the offset and count set to 0,3.
The line 5 will create a new String "Mon" in string pool and point to it.
But not sure what about line 6 whether it will behave like line 3 or line 5.

If i am wrong for line 2 or 4 also please correct..
Thanks

[Adeel Ansari]

Check out the source of substring() method. Then you will find out that line 5 is instantiating the new String object redundantly.

[Adeel Ansari]

This JR Thread might be helpful.

[Rob Spoor]

substring always creates a new String object, except when the substring would actually be the String itself (i.e. the start is 0 and the end is equal to the String length).