how to check if string contains '+' character [duplicate]

Question

I want to check if my string contains a + character.I tried following code

s= "ddjdjdj+kfkfkf";  if(s.contains ("\\+"){  String parts[] = s.split("\\+);   s=  parts[0]; // i want to strip part after  +  } 

but it doesnot give expected result.Any idea?

Answer 1

You need this instead:

if(s.contains("+")) 

contains() method of String class does not take regular expression as a parameter, it takes normal text.

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EDIT:

String s = "ddjdjdj+kfkfkf";  if(s.contains("+")) {     String parts[] = s.split("\\+");     System.out.print(parts[0]); } 

OUTPUT:

ddjdjdj 

Answer 2

Why not just:

int plusIndex = s.indexOf("+"); if (plusIndex != -1) {     String before = s.substring(0, plusIndex);     // Use before } 

It's not really clear why your original version didn't work, but then you didn't say what actually happened. If you want to split not using regular expressions, I'd personally use Guava:

Iterable<String> bits = Splitter.on('+').split(s); String firstPart = Iterables.getFirst(bits, ""); 

If you're going to use split (either the built-in version or Guava) you don't need to check whether it contains + first - if it doesn't there'll only be one result anyway. Obviously there's a question of efficiency, but it's simpler code:

// Calling split unconditionally String[] parts = s.split("\\+"); s = parts[0]; 

Note that writing String[] parts is preferred over String parts[] - it's much more idiomatic Java code.