How to Select All Text in HTML Text Input When Clicked Using JavaScript

It is pretty simple to select whole text on just a single click. You can use the following JavaScript code snippet:

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<!DOCTYPE html>
<html>
  <head>
    <title>Title of the Document</title>
  </head>
  <body>
    <div>
      Input Text:
      <input onClick="this.select();" type="text" value="Sample Text">
    </div>
  </body>
</html>

However, it does not work on mobile Safari. In such cases, you can use:

<!DOCTYPE html>
<html>
  <head>
    <title>Title of the Document</title>
  </head>
  <body>
    <div>
      Input Text:
      <input onClick="this.setSelectionRange(0, this.value.length)" value="Sample Text" />
    </div>
  </body>
</html>

The HTMLInputElement.select() method selects the entire text in a <textarea> element or <input> element that includes a text field.

But it becomes impossible to place the cursor at a desired point after focus. Here is another solution that combines all text selection on focus and as well as allows selecting a specific cursor point after focus:

<!DOCTYPE html>
<html>
  <head>
    <title>Title of the Document</title>
    <script src="https://code.jquery.com/jquery-3.5.0.min.js">
    </script>
  </head>
  <body>
    <div>
      Input Text:
      <input value="Sample Text" />
    </div>
    <script>
      $(function() {
        let focusedElement;
        $(document).on('focus', 'input', function() {
            if(focusedElement == this) return; // already focused, return so the user can place the cursor at a specific entry point
            focusedElement = this;
            setTimeout(function() {
              focusedElement.select();
            }, 100); //Select all text in any field in focus for easy re-entry. The delay is a bit to allow the focus to “stick” to the selection.
          });
      });
    </script>
  </body>
</html>

The HTMLElement.focus() method sets focus on the given element if it can be focused. By default, the focused element will receive keyboard and similar events.