javascript: a = b. Is it possible to change a but not influence b? : <p>Javascript Question. I am pretty new to javascript so pardon me if anything is not clear.</p>

<p>Please play following example at (right click) "inspect --> Console".</p>

<p>Example: </p>

<pre><code>o = [1,2,3];
y = o;
delete y[0];
y;// result: [undefined × 1, 2, 3]
o;// result: [undefined × 1, 2, 3]
</code></pre>

<p>Is it possible that the delete of <code>y</code> does not affect <code>o</code>? Here I made <code>y</code> equal to <code>o</code>. I just wanted to delete the first item of <code>y</code> but not <code>o</code>. However, <code>o</code> changes with <code>y</code> together. I wonder if it is possible to prevent <code>o</code> being changed even I change <code>y</code>?</p>
