window.onload vs $(document).ready()

The ready event occurs after the HTML document has been loaded, while the onload event occurs later, when all content (e.g. images) also has been loaded.

The onload event is a standard event in the DOM, while the ready event is specific to jQuery. The purpose of the ready event is that it should occur as early as possible after the document has loaded, so that code that adds functionality to the elements in the page doesn't have to wait for all content to load.

onload发生的时间要比ready要晚，ready是HTML文档加载完毕就发生，onload是所有东西都加载完毕才触发