Mystery Organism

tank4396 · January 23, 2021, 4:03am

Hello all, I am currently working on the mysterious organism challenge and I’m coming up with a TypeError where it doesn’t seem like a type error should exist.

gist.github.com

https://gist.github.com/codecademydev/7e7ab12293d7715ed3c84f09552fe1f2

main.js

// Returns a random DNA base
const returnRandBase = () => {
  const dnaBases = ['A', 'T', 'C', 'G']
  return dnaBases[Math.floor(Math.random() * 4)] 
}

// Returns a random single stand of DNA containing 15 bases
const mockUpStrand = () => {
  const newStrand = []
  for (let i = 0; i < 15; i++) {

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On line 20 where I am comparing the dna strand at index [randomNum] “This.dna[randomNum]” to the newBase, it appears that the randomly generated number is coming through as a string rather than a number. Can anyone help me see why this would be happening.

P.S. I have used a few different console.log statements to check that the newBase and randomNum variables are in fact their correct types.

tank4396 · January 23, 2021, 4:08am

UPDATE: It seems as if you do not need the this keyword when the method isn’t defined directly in the object itself. Removing the “this” keyword entirely from the code makes it function as expected.