The first program developed by jquery and the first program developed by jquery

The first program developed by jquery and the first program developed by jquery

I learned js and css some time ago, but I found that jquery was used in many programs. At that time, I was thinking about it first. I got familiar with js before doing this. Later I found that I couldn't do it, A lot of programs seem to be difficult, so I decided to take jquery seriously for a moment.
First, we can introduce the iquery file: jquery in the html page used.
Next, let's try the first jquery program.
Test.html

<! DOCTYPE html PUBLIC "-// W3C // dtd html 4.01 Transitional // EN" "http://www.w3.org/TR/html4/loose.dtd"> 

The running result is as follows:

We can find that $ (document). ready (function (){
}); Instead of using window. onload (), let's illustrate the difference between the two.