Answers for "js concat method in two arrays"

combine two arrays javascript

let arr1 = [0, 1, 2];
let arr2 = [3, 5, 7];
let primes = arr1.concat(arr2);

// > [0, 1, 2, 3, 5, 7]

concat multiple arrays in javascript

const concatArrays = (...arrays) => {
  let concatenatedArray = [];
  for(let i=0; i<arrays.length; i++){
    if(Array.isArray(arrays[i])){
    concatenatedArray.push(...arrays[i]);
  }
  else
  return false;
  }
  return concatenatedArray;
}