offset
UK[ˈɒfset] US[ˈɔ:fset]
vt. Offset; compensate; (for the purpose of comparison) to juxtapose (or Juxtapose); install a branch for (pipeline, etc.)
vi. form a branch, grow a branch; install a branch
n. start; set off; lithography; offset, compensate
adj. Branch; off-centre; offset; beginning
jquery offset() method syntax
Function: The offset() method returns or sets the offset (position) of the matching element relative to the document.
Return offset coordinates: Return the offset coordinates of the first matching element. The object returned by this method contains two integer properties: top and left, measured in pixels. This method only works on visible elements.
Syntax: $(selector).offset()
Set offset coordinates: Set the offset coordinates of all matching elements .
Syntax: $(selector).offset(value)
Parameters:
| Parameter | Description |
| value | Required. Specifies the top and left coordinates in pixels. Possible value: value pairs, such as {top:100,left:0}Object with top and left attributes |
Use the function to set the offset coordinates: Use a function to set the offset coordinates of all matching elements.
Syntax: $(selector).offset(function(index,oldoffset))
Parameters:
| Parameters | Description |
| function(index,oldoffset) | Specifies to return the new offset of the selected element function of coordinates. |
| index | Optional. Accepts the index position of the selector |
| oldvalue | Optional. Accepts the current coordinates of the selector. |
jquery offset() method example
<html>
<head>
<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
x=$("p").offset();
$("#span1").text(x.left);
$("#span2").text(x.top);
});
});
</script>
</head>
<body>
<p>本段落的偏移是 <span id="span1">unknown</span> left 和 <span id="span2">unknown</span> top。</p>
<button>获得 offset</button>
</body>
</html>Click the "Run instance" button to view the online instance