HTMLInputElement: required property

The required property of the HTMLInputElement interface specifies that the user must fill in a value before submitting a form. It reflects the <input> element's required attribute.

While the HTML boolean required attribute is ignored if the type is hidden, range, color, submit, reset, button, and image, the required property is true for these input types if the attribute is present, false otherwise.

If a required input doesn't have a value, the ValidityState object's read-only valueMissing property will be true.

const inputElement = document.getElementById("name");
console.log(inputElement.required);
inputElement.required = true;