Why isn't this code working?

Question

I tried to write a code where a svg circle's radius is changed using javascript but it did not work. Any help would be greatly appreciated.
https://code.sololearn.com/WeT12Yxt7vv1/?ref=app

Answer 1

Mohammad

change this line 12:
b['r']="30";

by this:
b.setAttribute('r',30);

alternative solution :
b.style['r']="30";

or
b.style.r="30";

You may omit quotation marks of value if you don't need to include units. Default unit would be pixels.

Answer 2

Omkar thanks a lot... it worked