Copy first element in an array and replace the last
<p>I have a javascript array with x amount of values.</p>

<p>How can I replace the last element in that array with the first? (Not switch positions but remove the last array and put the first in the last position)</p>

<p>Example:</p>

<p>Initial Array: [9, 14, 23 ,12 ,1]
Final Array: [9, 14, 23, 12, 9]</p>
