CODEWITHSUNDEEP
javastringescaping
Sandeep Rana
Sandeep Rana

Reputation: 3441

How to escape + character in java?

How to escape + character while using split function call in java?

split declaration

String[] split(String regularExpression)

thats what i did

services.split("+"); //says dongling metacharacter

services.split("\+"); //illegal escape character in string literal

But it allows to do something like this

String regExpr="+";

Upvotes: 11

Views: 6696

Answers (3)

ForemanBob
ForemanBob

Reputation: 138

Java and Regex both have special escape sequences, and both of them begin with \.

Your issue lies in writing a string literal in Java. Java's escape sequences are resolved at compile time, long before the string is passed into your Regex engine for parsing.

The sequence "\+" would throw an error as this is not a valid Java string.

If you want to pass \+ into your Regex engine you have to explicitly let Java know you want to pass in a backslash character using "\\+".

All valid Java escape sequences are as follows:

\t  Insert a tab in the text at this point.
\b  Insert a backspace in the text at this point.
\n  Insert a newline in the text at this point.
\r  Insert a carriage return in the text at this point.
\f  Insert a formfeed in the text at this point.
\'  Insert a single quote character in the text at this point.
\"  Insert a double quote character in the text at this point.
\\  Insert a backslash character in the text at this point.

Upvotes: 2

enzoyaaaaa
enzoyaaaaa

Reputation: 60

should be like this :

services.split("\\+");

Upvotes: 1

Konstantin Yovkov
Konstantin Yovkov

Reputation: 62854

Since the + is a regex meta-character (denoting an occurrence of 1 or more times), you will have to escape it with \ (which also has to be escaped because it's a meta-character that's being used when describing the tab character, the new line character(s) \r\n and others), so you have to do:

services.split("\\+");

Upvotes: 6

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