The opposite function of preventdefault()

The opposite function of preventDefault() does not exist. However, you can write a function as needed to undo the behavior of preventDefault(). First call preventDefault() in the event handler, and then immediately call this new function to undo the effect of preventing the default behavior. This new function resets the event's state so that the event's default behavior occurs normally.

In JavaScript, the opposite function of the preventDefault() method does not exist. preventDefault() is the default behavior used to prevent events, such as preventing the automatic submission of a form or preventing the jump of a hyperlink. Once preventDefault() is called, the event's default behavior is prevented.

However, you can write a function to undo the behavior of preventDefault() if needed. You can undo the effect of preventing the default behavior by first calling preventDefault() in the event handler and then immediately calling this new function. This new function resets the event's state so that the event's default behavior occurs normally.

The following is a simple example:

function allowDefault(event) {  
    event.preventDefault();  
    // 重新设置事件状态，使得默认行为可以正常发生  
    // 这取决于你的具体需求和事件的具体状态  
    // 这里只是一个示例，你可能需要根据实际情况进行调整  
    event.cancelable = true;  
}  
  
document.body.addEventListener('click', function(event) {  
    if (event.target.tagName === 'BUTTON' && event.target.textContent === 'Allow Default') {  
        allowDefault(event);  
    }  
});  
  
document.body.innerHTML = &#39;<button>Prevent Default</button><button>Allow Default</button><div>Some content</div>&#39;;

In this example, when you click the "Allow Default" button, the allowDefault() function will be called. This function first calls preventDefault() to prevent the default behavior, and then resets the event state so that the default behavior can occur normally. In this way, clicking the "Allow Default" button can restore the default behavior of the event.

Please note that this method is not completely reliable. Especially when there are dependencies between event handlers, simply calling preventDefault() and allowDefault() may not give the expected results. Therefore, in actual programming, you need to carefully consider how to use these functions to ensure that they behave as you expect.

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