html - 我需要在提交按钮上指定类型 ="submit"吗？

Question

以前，当我有一个只有一个提交按钮的表单时，我通常不会把 type="submit"属性在那里。我从来没有观察到这会导致问题，并且一直认为“提交”是按钮的默认类型并且我可以依赖这种行为。

但是，w3schools 和 MDN 对我的说法是否正确存在分歧。

w3schools claims:

Tip: Always specify the type attribute for the <button> element. Different browsers may use different default types for the <button> element.

鉴于MDN claims:

• submit: ... This is the default if the attribute is not specified, or if the attribute is dynamically changed to an empty or invalid value.

谁对谁错 - 无论是根据规范还是在真实浏览器中？

Answer 1

MDN 在其文章底部附近有一些规范链接，确认它所说的是正确的:button 元素的默认 type 是 submit.

W3C HTML 4.01 :

type = submit|button|reset [CI]
This attribute declares the type of the button. Possible values:

• submit: Creates a submit button. This is the default value.
• reset: Creates a reset button.
• button: Creates a push button.

W3C HTML5 :

The type attribute controls the behavior of the button when it is activated. It is an enumerated attribute. The following table lists the keywords and states for the attribute — the keywords in the left column map to the states in the cell in the second column on the same row as the keyword.

Keyword | State         | Brief description
--------+---------------+------------------
submit  | Submit Button | Submits the form.
reset   | Reset Button  | Resets the form.
button  | Button        | Does nothing. 

The missing value default is the Submit Button state.

W3Schools 的意思是，您应该始终指定该属性，以确保跨浏览器的行为尽可能一致。这并不意味着不能合法地省略该属性。