Why Does JavaScript onclick Function Trigger Prematurely When Parentheses Are Used?

The common pitfall is the improper use of parentheses when assigning the onclick attribute. Instead of sentNode.onclick = secondFunction(), which immediately executes the function, the correct syntax is sentNode.onclick = secondFunction. This assigns a reference to the function, which will only be executed upon the click event.

<code class="javascript">function startFunction() {
  var sentNode = document.createElement('a');
  sentNode.setAttribute('href', "#");
  sentNode.setAttribute('onclick', secondFunction);
  //sentNode.onclick = secondFunction();
  sentNode.innerHTML = "Sent Items";
  //...
}</code>

By omitting the parentheses, the onclick event is correctly bound to a function reference and not the result of its execution, ensuring the intended behavior.

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