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Ilya Nevolin
Ilya Nevolin

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Road to Genius: beginner #9

Each day I solve several challenges and puzzles from Codr's ranked mode. The goal is to reach genius rank, along the way I explain how I solve them. You do not need any programming background to get started, but you will learn a ton of new and interesting things as you go.

programming challenge

This challenge is a bit more complex than all previous ones we had. Solving it is very easy because you don't need to fully read the code. We need to fix the bug πŸ’§, which is used near the end of the code. It seems to be just a variable name, whose value is obtained from calling a function. To find πŸ’§, we can look at the next line, where there's a variable out which hasn't been declared yet, so πŸ’§ has to be out.

programming challenge answer

Solving the challenge was a piece of cake, but let's analyze the code, in particular the function range. This function takes two arguments x and y. It declares an empty array, then there's a while-loop which runs as long as x < y. Inside the loop, it adds a number to the array which is x + arr.length, and then it increments x's value by one. Finally it returns the array arr. So πŸ’§ (=out) points to the array (by reference).

If you feel inspired and motivated to upgrade your coding + debugging skills, join me on the Road to Genius at

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