The minLength property of the HTMLTextAreaElement interface indicates the minimum number of characters (in UTF-16 code units) required for the value of the <textarea> element to be valid. It reflects the element's minlength attribute. -1 means there is no minimum length requirement.
Note: If the textarea has a value, and that value has fewer characters than the minlength attribute requires, the element is considered invalid and the ValidityState object's tooShort property will be true.
A number representing the element's minlength if present or -1.
Given the following HTML:
<p>
<label for="comment">Comment</label>
<textarea id="comment" minlength="10" maxlength="200"></textarea>
</p>You can use the minLength property to retrieve or set the <textarea>'s minlength attribute value:
const textareaElement = document.querySelector("#comment");
console.log(`Element's minLength: ${textareaElement.minLength}`); // "Element's minlength: 10"
textareaElement.minLength = 5; // updates the element's minlength attribute value