JSFiddle - React, Tailwind, and code Playground

HTML

<table id="myTable"> 
<tr>
    <td>
        5
    </td>
</tr>
<tr>
    <td>5
    </td>
</tr>
<tr>
    <td>
    5</td>
</tr>
<tr>
    <td>5 </td>
</tr>
<tr>
    <td>foobar</td>
</tr>
<tr>
    <td>5</td>
</tr>
</table>

JavaScript

function RowExists(table,columnValue) {
    for(var i=0; i < table.rows.length; i++) {
        console.log('checking ' + table.rows[i].cells[0].firstChild.nodeValue + ' against value ' + columnValue);
        
        if (table.rows[i].cells[0].firstChild.nodeValue === columnValue) {
            console.log('found at index ' + i);
        }
     }
}

RowExists(document.getElementById('myTable'), '5');