title: compactmap could not cast the number
body: <p>I am retrieve the account details from my API show to collection view and I need to show my account number on the section header. My JSON look like below</p>
  <pre><code>  {
      &quot;data&quot;: [{
              &quot;TxnIndicator&quot;: &quot;Cr&quot;,
              &quot;AccountNumber&quot;: 345678901112345,
              &quot;MBLTxnCode&quot;: &quot;MBLT908&quot;,
              &quot;TxnCurrency&quot;: &quot;IRR&quot;,
              &quot;TransactionAmount&quot;: 2000,
              &quot;AccLvlSuddenSurgeValue&quot;: &quot;BUS-ST-ACCLVLVALUE-NSTR-001&quot;
          },
          {
              &quot;TxnIndicator&quot;: &quot;Cr&quot;,
              &quot;AccountNumber&quot;: 345696289714492,
              &quot;MBLTxnCode&quot;: &quot;MBLT969&quot;,
              &quot;TxnCurrency&quot;: &quot;KRW&quot;,
              &quot;TransactionAmount&quot;: 1000,
              &quot;AccLvlSuddenSurgeValue&quot;: &quot;BUS-ST-ACCLVLVALUE-NSTR-001&quot;
          },
          {
              &quot;TxnIndicator&quot;: &quot;Cr&quot;,
              &quot;AccountNumber&quot;: 345696289714492,
              &quot;MBLTxnCode&quot;: &quot;MBLT943&quot;,
              &quot;TxnCurrency&quot;: &quot;KRW&quot;,
              &quot;TransactionAmount&quot;: 30000,
              &quot;AccLvlSuddenSurgeValue&quot;: &quot;BUS-ST-ACCLVLVALUE-NSTR-001&quot;
          },
          {
              &quot;TxnIndicator&quot;: &quot;Dr&quot;,
              &quot;AccountNumber&quot;: 263196281214407,
              &quot;MBLTxnCode&quot;: &quot;MBLT618&quot;,
              &quot;TxnCurrency&quot;: &quot;NPR&quot;,
              &quot;TransactionAmount&quot;: 20000,
              &quot;AccLvlSuddenSurgeValue&quot;: &quot;BUS-ST-ACCLVLVALUE-STR-001&quot;
          }
      ]
  }
  </code></pre>
  <p>I am using <strong>compactmap</strong> functions for aligning  headers. I am using below code</p>
  <pre><code>self.headerArr = strreports.compactMap {$0[Array(self.arrValue[0].keys)[0]]} as! [String]
  </code></pre>
  <p>I can't use codable method because all the keys are unknown. we will know only on run time. when i try to above method i will get the error could not cast the number to string.  how to resolve this?</p>