Why are there such tasks? Which do not reflect the specifics of the language, and forced to perform arithmetics operation? They have no sense.
What is the output of this code?
var a = "I love coding";
a = a+a+a[a.length-5]+a;
This specific one is simple and made for beginners to test their knowing that counting starts from 0 and that the last character is length-1 not length. It seams simple, but for people just starting it's hard enough to used to it. Anyway challenges are created mostly by users and get approved by users too. So SoloLearn doesn't take a big part in it.