问题
I have the following code set up in my footer which adds a class of 'day' during the time specified.
function setTimeStyles() {
var currentTime = new Date().getHours();
if(currentTime > 5 && currentTime < 17) {
document.body.className = 'day';
}
}
$(document).ready(function() {
setTimeStyles();
});
The problem is when the class gets added, it gets rid of the other classes already in place. For example, without the 'day' class added, my body tag would be:
<body class="home">
But when the 'day' class is added, my body tag turns into:
<body class="day">
I'd like it so that the 'day' class gets added to what's already there like this:
<body class="home day">
How can I go about doing this?
回答1:
In jQuery you can do
$("body").addClass("day");
回答2:
Have you tried replacing
document.body.className = 'day';
with
document.body.className = document.body.className + ' day';
回答3:
I don't know how jquery adds a class, but you may want to be sure it is added (or moved) to the end of any existing list, giving it precedence in any collisions.
function addClass(node, cname){
var C= node.className.split(/\s+/), L= C.length;
while(L){
if(C[--L]=== cname) delete C[L];
}
C.push(cname);
node.className= C.join(' ').replace(/ {2,}/g,' ');
}
来源：https://stackoverflow.com/questions/4660590/how-do-i-add-a-class-without-having-it-get-rid-of-the-others