How to Get the Caret Position in a Text Input Field?

How to Retrieve the Caret Position in a Text Input Field

Obtaining the cursor position within a text input field is essential for various tasks, such as form validation and text editing. The jQuery framework provides a simple solution to this problem.

jQuery Method:

The caretPosition() plugin is a convenient way to retrieve the caret position. Simply call the following function on the desired input field:

$("input#myInput").caretPosition();

This method returns the caret position as an integer value, representing the character index within the input field.

Native Browser Methods:

Alternatively, you can use native browser methods to retrieve the caret position. These methods vary depending on the browser, but here are the most common:

• Internet Explorer: Use the selectionStart property of the input field.
• Firefox: Use the selectionStart and selectionEnd properties of the input field.

Example:

The following example demonstrates how to retrieve the caret position using native JavaScript:

function getCaretPosition(inputField) {
  // Initialize caret position to 0
  var caretPos = 0;

  // IE support
  if (document.selection) {
    inputField.focus();
    
    // Get empty selection range to find cursor position
    var selectionRange = document.selection.createRange();
    selectionRange.moveStart('character', -inputField.value.length);
    
    // Caret position is the length of the selection
    caretPos = selectionRange.text.length;
  }

  // Firefox support
  else if (inputField.selectionStart || inputField.selectionStart == '0') {
    // Caret position is the selection start or end, depending on the direction
    caretPos = inputField.selectionDirection == 'backward' ? inputField.selectionStart : inputField.selectionEnd;
  }

  return caretPos;
}

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