Determine if CSS property is set to a certain value?

问题

Just wondering how to determine a jQuery statement like this

if( $("#test").css('display', 'block') == true) {
   return true;
}

Basically, I want to be able to determine IF an element has is currently being shown or hidden via the "display:block" attribute ?

回答1:

Use

if( $("#test").css('display') == 'block') {

I'm fairly sure .css(), returning a calculated value, will always return a lower case result - the docs say nothing on this. To make totally sure, you could do a

if( $("#test").css('display').toLowerCase() == 'block') {

while you can rely on display giving reliable results, note that some CSS properties will not always show up the way they were defined. For example

a { color: red }

will turn out rgb(255,0,0); when queried using .css().

回答2:

You can use isvisible and is hidden also

if ( $('#test').is(':visible')){

回答3:

I think the only way to test this is by comparing with actual values:

function displayHidden(elem) {
    return $(elem).css('display') === 'hidden';
}

来源：https://stackoverflow.com/questions/5928920/determine-if-css-property-is-set-to-a-certain-value