Beginner Exercism • javascript

Nucleotide Count

Challenge Overview

Each of us inherits from our biological parents a set of chemical instructions known as DNA that influence how our bodies are constructed. All known life depends on DNA!

Source: Exercism javascript/nucleotide-count

💡 View Solution

export class NucleotideCount {
  static parse(dna) {
    if (/[^ACGT]/.test(dna)) throw new Error('Invalid nucleotide in strand');
    const counts = { A: 0, C: 0, G: 0, T: 0 };
    for (const char of dna) counts[char]++;
    return `${counts.A} ${counts.C} ${counts.G} ${counts.T}`;
  }
}