Differences between onload and $ (document). Ready ()

Onload needs to be executed after all resources on the page are loaded, while ready is when the DOM document tree has been parsed, ready is faster than onload. For example, a large image is displayed on a page, which takes a long time to load. onload is executed only after the image is loaded, while ready does not have to wait until the image is loaded.

In $ (document ). when ready () is executed, the entire DOM document tree has been parsed, that is, each Dom element can be accessed (but the access to some attributes of some elements may not be accurate at this time, width and height of the slice ). $ (Function () {}) can be placed after it, possibly before ready.

 

 

 

1. It is onload, not onload.
2. No document. onload, only window. onload.
3. Window. onload = myfunction, rather than window. onload = myfunction (). If it is written as the latter, when it is executed here, it calculates the return value of myfunction () and passes it to window. onload. Only write the former, and direct the myfunction to window. onload (similar to the pointer variable in C)