recursive function call

recursive.js

const arr =
  [
    [
      [1, 2, 3],
      [4, 5, 6],
    ],
    [
      [7, 8, 9],
      [10, 11, 12],
    ]
  ];

const isNumberArray = (arr) => {
  return arr.every(item => {
    return typeof(item) === 'number' && !Number.isNaN(item);
  })
};

const walk1 = (arr) => {
  if (isNumberArray(arr)) {
    console.log(`arr is [${arr}]. walk ended.`);
  } else {
    for (const a of arr) {
      walk1(a);
    }
  }
}
function walk2(arr) {
  if (isNumberArray(arr)) {
    console.log(`arr is [${arr}]. walk ended.`);
  } else {
    for (const a of arr) {
      walk2(a);
    }
  }
}

walk1(arr);
walk2(arr);

const walk = function() { 
  // something
  walk();  
}

function walk() { 
  // something
  walk();
}

どちらでも再帰できる。