Javascript点击事件需要双击

Question

I have a simple HTML-CSS-JavaScript page with an event listener on a button to toggle a div.

However, all is working but the animation function takes two clicks first time to work, although i consoled the click event to prove that the button listens to the first click too.

i tried to wrap into window.onload but same thing.

note: i want to use pure javascript only. thank you

this pic shows the first click (it says "clicked" in the console):

this pic shows the second click (animation took place):

Here is my code:

            var showDivButton = document.getElementById('showDivButton');
            var info =  document.getElementById('info');

            showDivButton.addEventListener('click', animation) ;

            // animation func
            function animation () { 
                console.log('Clicked!');
                if (info.style.display === 'none'){
                    info.style.display =  'inline-block';
                    showDivButton.style.background = 'green';
                } else {
                     info.style.display =  'none';
                     showDivButton.style.background = 'gray';
                }

            }

Look at My Plunker Here please. Thank you in advance.

Answer 1

Try to revise your function block as follow:

function animation () { 
    console.log('Clicked!');
    if (info.style.display == '' || info.style.display == 'none'){
        info.style.display =  'inline-block';
        showDivButton.style.background = 'green';
    } else {
         info.style.display =  'none';
         showDivButton.style.background = 'gray';
    }

}

info.style.display is '' on initial

Answer 2

Because info.style.display refers to the style attribute of your div, not the computed Style, so on the first click, this is not set.

You may want to look at getComputedStyle , but i would advise switching class instead of directly modifying style.