Three message boxes are created in JavaScript: Warning box, confirmation box, prompt box.

Website: http://www.w3school.com.cn/js/js_popup.asp

Warning Box

Warning boxes are often used to ensure that users can get some information.

When the warning box appears, the user needs to click the OK button to continue the operation.

Grammar:

Alert ("Text")

Confirmation box

The confirmation box is used to enable users to verify or accept certain information.

When the confirmation box appears, the user needs to click the OK or Cancel button to continue the operation.

If the user clicks Confirm, then the return value is true. If the user clicks Cancel, the return value is false.

Grammar:

Confirm ("text")

Prompt box

The prompt box is often used to prompt the user to enter a value before entering the page.

When the prompt box appears, the user needs to enter a value and then click the Confirm or Cancel button to continue the manipulation.

If the user clicks Confirm, then the return value is the value entered. If the user clicks Cancel, the return value is null.

Grammar:

Prompt ("text", "Default value")

Three message boxes are created in JavaScript: Warning box, confirmation box, prompt box.