String.split returning null when using a dot

Question

I got this simple code: ``` String ip = "1.2.3.4"; String[] ipArray = ip.split("."); System.out.println(ipArray[1]); ``` And `ipArray` is null by the time it hits `System.out.println` (throws null pointer exception). My question is why does ipArray stay null even though I'm setting it to split on each of ip's .s?

Accepted Answer

Use `ip.split("\.");` and your problems will be solved. The problem is that String#split receives a regular expression, the dot (.) symbol is a special character in regular expressions, so you need to escape it for it to be interpreted as a plain dot, also as the backslash is an escape character in Java, you have to escape it too.

String.split returning null when using a dot

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