1. console.log is the most commonly used input method, normalizes output statements, and also has print placeholder integers (%d||%i), floating point numbers (%f), objects (%o), characters (%s) );
2. console.error outputs the wrong statement
3. console.info outputs an informational statement
4. console.warn outputs a warning statement
5, console.dir can view the information in the statement
6, console.group input grouping
7. console.assert judges whether the parameter is true (== represents the same value, === represents the same value and type)
8, console.trace; follow the vine, trace the function trace
9. console.time records the loaded time
10. The console.profile performance analysis (the number of times the page is refreshed per second) tells you that I will not, haha,
Other methods will not be discussed for the time being. What is to be discussed is where so many underfined outputs come from
