To determine the scroll bar to the bottom of the JS code _javascript skills

To determine the scroll bar to the bottom, you need to use the DOM's three property values, namely ScrollTop, ClientHeight, ScrollHeight.

ScrollTop is the scroll distance of the scroll bar on the y-axis.

ClientHeight is the height of the content viewable area.

ScrollHeight adds an overflow (scrolling) distance to the height of the content viewable area.

From the introduction of this three attributes can be seen, the scroll bar to the bottom of the condition is scrolltop + clientheight = = ScrollHeight.

Nonsense not much said, hurriedly on the code (compatible with different browsers).

Copy Code code as follows:

The scroll distance of the scroll bar on the Y axis

function Getscrolltop () {
var scrolltop = 0, bodyscrolltop = 0, documentscrolltop = 0;
if (document.body) {
Bodyscrolltop = Document.body.scrollTop;
}
if (document.documentelement) {
Documentscrolltop = Document.documentElement.scrollTop;
}
ScrollTop = (bodyscrolltop-documentscrolltop > 0)? Bodyscrolltop:documentscrolltop;
return scrolltop;
}

Total height of the document

function Getscrollheight () {
var scrollheight = 0, bodyscrollheight = 0, documentscrollheight = 0;
if (document.body) {
Bodyscrollheight = Document.body.scrollHeight;
}
if (document.documentelement) {
Documentscrollheight = Document.documentElement.scrollHeight;
}
ScrollHeight = (bodyscrollheight-documentscrollheight > 0)? Bodyscrollheight:documentscrollheight;
return scrollheight;
}

Height of browser viewport

function Getwindowheight () {
var windowheight = 0;
if (Document.compatmode = = "Css1compat") {
WindowHeight = Document.documentElement.clientHeight;
}else{
WindowHeight = Document.body.clientHeight;
}
return windowheight;
}

Window.onscroll = function () {
if (getscrolltop () + getwindowheight () = = Getscrollheight ()) {
Alert ("You are in the bottom!");
}
};

It's easier if you do it in jquery,

Copy Code code as follows:

$ (window). Scroll (function () {
var scrolltop = $ (this). ScrollTop ();
var scrollheight = $ (document). Height ();
var WindowHeight = $ (this). Height ();
if (scrolltop + windowheight = = scrollheight) {
Alert ("You are in the bottom");
}
});

If you want to determine whether the scroll bar in one element is in the bottom, according to similar ideas, Change the document.body to a specific element, the way to get scrolltop and ScrollHeight is the same, but get the height of the element visible need to use the offsetheight attribute, directly according to gourd painting ladle can.