Web front-end Questions (iv)

1, Wiindow.onload and $ (document). The difference between ready

Window.onload can only appear once, $ (document). Ready can appear multiple times

Window.onload needs to wait until all the files have been loaded before loading, $ (document). Ready just wait for the document structure to load and start loading

2. What operations can cause memory leaks?

A memory leak refers to any object that persists after it is no longer owned or needed

(1) settimeout A memory leak when the first parameter is a string rather than a function

(2) Closures

(3) Console log

(4) Loop (two objects referencing each other and preserving each other)

Web front-end Questions (iv)