如何使用JS手动弹出所需的文本字段警报？

Question

Do anyone know how to trigger this popup using JS?

I know by default it triggered by clicking submit type button when the text field is inside area.

I have my own Boostrap modal alert popup when I click submit button without filling up required text field. So once the modal alert is being dismissed, I want that default JS alert trigger after that.

Answer 1

What you're asking about is HTML5 Constraint Validation.

https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation

For your specific example, you can use the required attribute.