String.contains in Java
<pre><code>String s1 = "The quick brown fox jumps over the lazy dog";
String s2 = "";
boolean b = s1.contains(s2);
System.out.println(b);
</code></pre>

<p>I run the Java code above, the b return true.
Since s2 is empty, why does s1 contains s2?</p>

<p>I check the Java API, it write:</p>

<p>Returns true if and only if this string contains the specified sequence of char values. </p>

<p>Parameters:
s - the sequence to search for 
Returns:
true if this string contains s, false otherwise</p>
