How to select all diagonal cells in table ?

<table border="1" style="width:100%" id="table">

1.1
2.1
3.1
4.1
5.1


1.2
2.2
3.2
4.2
5.2


1.3
2.3
3.3
4.3
5.3


1.4
2.4
3.4
4.4
5.4


1.5
2.5
3.5
4.5
5.5

<br> let tableEl = document.getElementById(&quot;table&quot;);<br> let tableRows = document.querySelectorAll(&quot;table tr&quot;);</p> <div class="highlight"><pre class="highlight plaintext"><code>let ind=0; while(tableRows[ind]){ tableRows[ind].cells[ind].style.backgroundColor = "red"; ind++; } &lt;/script&gt; </code></pre></div>