Thanks

It depends on what language you're using, but all you have to do is output the variable that is given to you to the console.

Python:       print(string)
JavaScript:   console.log(str)
CoffeeScript: console.log(str)
Ruby:         print(string)  /   puts(string)

how can i do this?

It's a hex value. You should print the input if you want to know any of the test cases.

what is 5th test in "should return NaN for non-integer strings"?