String.contains in Java

Question

``` String s1 = "The quick brown fox jumps over the lazy dog"; String s2 = ""; boolean b = s1.contains(s2); System.out.println(b); ``` I run the Java code above, the b return true. Since s2 is empty, why does s1 contains s2? I check the Java API, it write: Returns true if and only if this string contains the specified sequence of char values. Parameters: s - the sequence to search for Returns: true if this string contains s, false otherwise

Accepted Answer

Empty is a subset of any string.

Think of them as what is between every two characters.

Kind of the way there are an infinite number of points on any sized line...

(Hmm... I wonder what I would get if I used calculus to concatenate an infinite number of empty strings)

Note that "".equals("") only though.

String.contains in Java

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