javascript - When I access to a key, I want its value and set it in an array. The access is by using strings

Question

https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/dna-pairing When I access to a key, I want its value and set it array. The way I try to access is with a string. For example: GCG. Therefore, I want to get

[["G", "C"], ["C","G"],["G", "C"]]

How may I do that?

function pairElement(str) {
  let dna = {
         "A": "T",
         "C": "G",
         "T": "A",
         "G": "C"
     }
}

pairElement("GCG");

Answer 1

Although I'm not exactly sure on what you want to do, this does give the output you're expecting.

function pairElement(str) {
    const dna = {
        "A": "T",
        "C": "G",
        "T": "A",
        "G": "C"
    }
    let arr = [];
    for (const key of str){
        arr.push([key, dna[key]])
    }
    return arr;
}

// some input tests
console.log(pairElement("GCG"));
console.log(pairElement("ACTG"));
console.log(pairElement("CCGAT"));