Hey there! Let's fix that visibility toggle issue you're having. The problem comes down to a small syntax error in your JavaScript code, but it's easy to correct.

What Went Wrong in Your Original Code #

Looking at your JS snippet:

$('#url').on('change keyup paste',function(){ $('#msg')style.visibility('visible');});

Two issues are breaking it:

• You’re missing the dot operator between the jQuery object $('#msg') and style – but even if you added that, using native DOM properties directly with a jQuery object isn't the cleanest approach here.
• The syntax for setting the visibility property is incorrect: native DOM uses assignment (= 'visible'), not a function call, and jQuery has its own dedicated method for modifying CSS.

Corrected jQuery Code #

Here's the working version using jQuery's .css() method, which is the proper way to adjust CSS properties with jQuery:

$('#url').on('change keyup paste', function() {
  $('#msg').css('visibility', 'visible');
});

How This Works #

• $('#url').on('change keyup paste', ...): This part is actually correct! It properly listens for the three events you specified on the #url element.
• $('#msg').css('visibility', 'visible'): The .css() method takes two arguments: the name of the CSS property you want to change, and its new value. This will update the visibility property of your #msg element to visible, making it show up as intended.

Alternative: Plain JavaScript (No jQuery) #

If you prefer to skip jQuery and use native JS instead, here's an equivalent version:

// Get references to the elements
const urlInput = document.getElementById('url');
const msgElement = document.getElementById('msg');

// Create a reusable function to show the message
function showMessage() {
  msgElement.style.visibility = 'visible';
}

// Attach event listeners
urlInput.addEventListener('change', showMessage);
urlInput.addEventListener('keyup', showMessage);
urlInput.addEventListener('paste', showMessage);

Quick Troubleshooting Tip #

If you're using jQuery, double-check that you've included the library before your custom script. If jQuery isn't loaded, the $ function will be undefined, and your code won't run:

<!-- Include jQuery first -->
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<!-- Then your custom script -->
<script>
  // Your corrected code here
</script>

内容的提问来源于stack exchange，提问作者 elison