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JavaScript JavaScript Numbers The Math Object Random Number Challenge – Solution

How does the program know that the highNumber variable is a number and execute the first if statement?

And if not the else statement is executed?

4 Answers

Hey Caloline,

This got me for a sec too, but here's the solution:

Before he goes to the if statement, he's parsing the number from the user input via the parseInt() method.

The user either enters something that can be parsed into a number, or the parseInt() method returns NaN, which then evaluates to false.

Read more about why NaN evaluates to false and other falsy values here: https://developer.mozilla.org/en-US/docs/Glossary/Falsy


With the parseInt() method.


Skyler Harris
Skyler Harris
7,670 Points

Nice answer Steve that made a lot of sense!

Georgia Lloyd
Georgia Lloyd
3,384 Points

Thanks, I was also wondering this