I'm doing some testing in chrome debugger tool, I find some strange numbers are printed below the texts output by console.log:
I didn't log in the console, why are they there? what are these numbers? what does it mean?
The Chrome console logs the value of the last expression executed. In the first example above, the last line, i++; logs 9. In the second example, i+=1; logs 10.
来源：https://stackoverflow.com/questions/33604144/whats-the-meaning-of-the-numbers-printed-below-the-message-of-console-log