How to zip two arrays into one array which every array contains another array-CodePudding

I would like to "zip" values from two arrays into 1 array. E.g. I got an array with titles: ['Cukier biały premium', 'second item'] and the second array with quantity of the titles [1, 999] i.e. Cukier biały premium quantity is 1 and should be in array and so on.. and I'd like to get an array with values of these two arrays from index[0] and so on. But the problem is that inside this two arrays are more arrays inside: I got

 const productTitles = order.map((item) => item.productTitle);
  const productQuantity = order.map((item) => item.quantity);
  console.log('product titles', productTitles); // output:  [Array(2), Array(3)] 
  console.log('product quantities', productQuantity); // output: [Array(2), Array(3)]

  const merged = productTitles.map((title, i) => [title, productQuantity[i]]);

How to Zip the merged array to got data like: ["Cukier biały premium", 1] and ["second item", 999] in one array and so this is order 1 () that I can .map over and display it in orders page? the second array (order 2) should contain an array of ["Cukier biały premium", 1], [Cukier czarny, 1], [Cukier amerykanski, 1]

Tried like this but got an array of [undefined, undefined]

const merged2 = productTitles.map((title, i) => {
    productQuantity.map((quantity, index) => {
      [title[i], quantity[index]];
    });
  });

CodePudding user response：

You had the right basic idea. Issue you had is you were mixing up the indexes. And you were not returning anything in the map calls.

const productTitles = [
  ['a', 'aa'],
  ['b', 'bb'],
];

const productQuantity = [
  [1, 11],
  [2, 22],
];

const merged2 = productTitles.map((row, rowIndex) =>
  row.map((value, columnIndex) => [value, productQuantity[rowIndex][columnIndex]]));

console.log(merged2);


// Use flatMap if you do not want a nested array

const mergedFlat = productTitles.flatMap((row, rowIndex) =>
  row.map((value, columnIndex) => [value, productQuantity[rowIndex][columnIndex]]));

console.log(mergedFlat);

CodePudding user response：

Short solution but not performant for big list since we call productQuantity.flat() on every iteration:

productTitles.flat().map((p, i) => [p, productQuantity.flat()[i]])

CodePudding user response：

have your tried destructuring the array