I am new to java regex.I saw this in Docs:
$ The end of a line
But when I try this snippet:
String str = "firstline\r\nsecondline";
String regex = "$";
System.out.println(str.replaceAll(regex, "*"));
I guess result will be:
firstline*
secondline*
But I see this result:
firstline
secondline*
It seems that it $ only matches the end of a String. So why do the docs say it matches "The end of a line"?
You must enable multiline mode, then $ will match both, the end of a line and the end of the input:
http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#MULTILINE
i.e.:
Pattern.compile("$",Pattern.MULTILINE);
You can also use the flag expression (?m), i.e.:
Pattern.compile("(?m)$");
The oracle docs you cite are really quite imprecise here. The documentation of the pattern class (link above) is more precise and should be your reference for Java RegExs.
$ means end of input, not end of line.
However, this is easily solved using the "multi line" flag; change your regex to add (?m) at the front:
String regex = "(?m)$";
The multi line flag makes caret ^ and dollar $ match start and end of lines
It's definitive for the end of your input. If you have newline literals in your input, the $ will not match them.
If you want to match every newline, something like:
str.replaceAll("(\r\n|$)", "*$1");
might work.
