JavaScript

Question

Hello )
Help me to understand that:

alert( 20e-1['toString'](2) ); // result = 10

Answer 1

Another tricky one.
20e-1 is actually 2.
2['toString'](2) calls the toString() method on the object 2 and converting it to a string. the last catch here is that the parameter 2 passed to toString is the radix in which the string conversion is done.
when you convert 2 to base 2,you get 10.

perhaps this will be clearer:

var x=20e-1;
alert (x.toString(2));

Answer 2

And again ) Thank you )

Answer 3

Your explanation is very clear.