Methods to disable and undisable page buttons_javascript skills

The concept of timer and delayer
//--Timer
// Timer ID number setInterval(callback function, milliseconds);
// Call the callback function every specified milliseconds

// clearInterval (timer ID number)
// Stop the timer with the specified ID number (actually destroying and releasing resources)

//--Delayer
// Delayer ID number setTimeout (callback function, millisecond interval)
// Starting from the call, wait for the specified number of milliseconds and call the callback function once, then end
// Use clearTimeout to clear the delayer

Rendering:

After the page is opened, the following picture will appear: After that, the button value value will decrease by 1 every 1 second until 0. The stop button content will change to agree



Implementation code:

Copy code The code is as follows:

< ;html xmlns="http://www.w3.org/1999/xhtml">