How to load the JS_javascript skills of google-analytics (or other third parties)

Many websites use google-analytics or other analysis websites to obtain the statistics of users' website visits. (google-analytics (ga) is used in the following discussion ). After registering ga, ga will generate a js script, which many people directly copy(Including the blog, CSDN, and BlogJava ). But is the JS automatically generated by ga the most reasonable?

How is it reasonable? How is it unreasonable? Because ga is only an analysis tool, its use cannot affect our program. If it affects, it is unreasonable. It is reasonable.

Current ga usage:
Let's take a look at the js script automatically generated by ga, as shown below:

The Code is as follows: