使用jQuery循环设置CSS属性

Question

I am trying to use a jQuery loop to set a variable that will change in each pass through the loop. the variable would then be applied to a css property. the problem I have is that every css property with the variable has the same value (which is the value at the end of the loop).

pageArray = new Array('web1','web2','web3','web4');
    **leftTabHeight** = 0;
for (var p=0;p<pageArray.length;p++){
    **leftTabHeight** = parseFloat(p) *100;
    $('.left.main').addClass('flip_left');
    $('.left.main').css({'width':'482px', 'height':'668px', 'z-index':'11','background':'url("images/snake_tab.png") no-repeat, url("images/book_left_main.png") no-repeat','background-position': '0px '+**leftTabHeight**+'px, 42px 42px','position':'absolute'});

};

HTML:

<div class="web4 left main">
    <h3 class="left_button">web 4</h3>
<h4>web 4</h4>
<p>Stuff</p>
</div>
<div class="web4 left bind">    
</div>

<div class="web3 left main">
<h3 class="left_button">web 3</h3>
<h4>web 3</h4>
<p>stuff</p>
</div>
<div class="web3 left bind">    
</div>

<div class="web2 left main">
<h3 class="left_button">web 2</h3>
<h4>web 2</h4>
<p>Stuff</p>
</div>
<div class="web2 left bind">    
</div>

<div class="web1 left main">
<h3 class="left_button">web 1</h3>
<h4>web 1</h4>
<p>Stuff</p>
</div> 
<div class="web1 left bind">    
</div>

So I want each class to have a background image that is positioned differently. currently they all stack on top at 300px.

Thanks

So, I've placed a console.log(leftTabHeight) within the loop and it does print 0, 100, 200, 300. The 300 is the only one being applied.

Answer 1

You could do something like:

var variable_position = 0;
$('.background_image').each(function(){
  $(this).css('background-position', '0px ' + variable_position + 'px 42px 42px');
  variable_position += 100;
});

That is assuming your objects that need this have the class "background_image".

Answer 2

Okay I've figured this out the problem was I each time the function looped it rewrote all the divs. I needed to add the third class into the jQuery selection as a variable. so this code works:

pageArray = new Array('snake','web_s','web1','web2','web3','web4');
var leftTabHeight = 0;
for (var p in pageArray){
    leftTabHeight = parseFloat(p *100);
    $('.'+pageArray[p]+'.left.main').addClass('flip_left');
    $('.'+pageArray[p]+'.left.main').css({'width':'482px', 'height':'668px', 'z-index':'11','background':'url("images/snake_tab.png") no-repeat, url("images/book_left_main.png") no-repeat','background-position': '0px '+leftTabHeight+'px, 42px 42px','position':'absolute'});
};

Answer 3

问题是您要引用所有".left.main“项。将这些行更改为$('.'+pageArray[p]+'.left.main').css(...) ，它。