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copied!<p>Actually, in Java, the <strong>references are passed-by-value</strong>.</p> <p>In this case, the reference is a <code>byte[]</code> object. Any changes that affect the object itself will be seen from the caller method.</p> <p>However, if you try to replace the reference, for example using <code>new byte[length]</code>, you are only replacing the reference that you obtained by pass-by-value, so you are not changing the reference in the caller method.</p> <p>Here's an interesting read about this issue: <a href="http://javadude.com/articles/passbyvalue.htm" rel="noreferrer">Java is Pass-by-Value Dammit!</a></p> <hr> <p>Here's an concrete example:</p> <pre><code>public class PassByValue { public static void modifyArray(byte[] array) { System.out.println("Method Entry: Length: " + array.length); array = new byte[16]; System.out.println("Method Exit: Length: " + array.length); } public static void main(String[] args) { byte[] array = new byte[8]; System.out.println("Before Method: Length: " + array.length); modifyArray(array); System.out.println("After Method: Length: " + array.length); } } </code></pre> <p>This program will create a <code>byte</code> array of length <code>8</code> in the <code>main</code> method, which will call the <code>modifyArray</code> method, where the a new <code>byte</code> array of length <code>16</code> is created.</p> <p>It may appear that by creating a new <code>byte</code> array in the <code>modifyArray</code> method, that the length of the <code>byte</code> array upon returning to the <code>main</code> method will be <code>16</code>, however, running this program reveals something different:</p> <pre><code>Before Method: Length: 8 Method Entry: Length: 8 Method Exit: Length: 16 After Method: Length: 8 </code></pre> <p>The length of the <code>byte</code> array upon returning from the <code>modifyArray</code> method reverts to <code>8</code> instead of <code>16</code>.</p> <p>Why is that?</p> <p>That's because the <code>main</code> method called the <code>modifyArray</code> method and sent <strong>a copied reference to the <code>new byte[8]</code></strong> by using <strong>pass-by-value</strong>. Then, the <code>modifyArray</code> method <strong>threw away the copied reference by creating a <code>new byte[16]</code></strong>. By the time we leave <code>modifyArray</code>, the reference to the <code>new byte[16]</code> is out of scope (and eventually will be garbage collected.) However, the <code>main</code> method still has reference to the <code>new byte[8]</code> as it only <strong>sent the copied reference</strong> and not an actual reference to the reference.</p> <p>That should demonstrate that Java will pass reference using pass-by-value.</p>

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