indexOf is not a function
<p>I' am currently working with the following code. In the console it's throwing </p>

<blockquote>
  <p>Uncaught TypeError: TotalAccountBalance.indexOf is not a function</p>
</blockquote>

<p>I don't know what else to do. Searching didn't help much.</p>

<pre><code>var CurrentPreservedBalance, CurrentGeneralAccountBalance, TotalAccountBalance;
    CurrentPreservedBalance = '20.56';
    CurrentGeneralAccountBalance = '20.56';
    if( CurrentPreservedBalance &amp;&amp; CurrentGeneralAccountBalance ){
        TotalAccountBalance = +CurrentPreservedBalance + +CurrentGeneralAccountBalance;
        console.log( TotalAccountBalance.indexOf('.') );
    } else {
        $('#total-fnpf-account-balance').val('$0.00');
        $('#total-account-balance').val('$0.00');
    }
</code></pre>