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Turning two arrays into an object : one array as keys and the other array as values

March 27, 2023

I have two arrays:
[ 'J', 'o', 'h', 'a', 'n']
[ 1, 1, 1, 2, 1]
I would like to use the first one as the object keys and the second one as object values. The result should be:
{ "J": 1, "o": 1, "h": 1, "a": 2, "n": 1}

Is this achievable with JavaScript ?

>Solution :

You can use Array.prototype.reduce to iterate over the arrays and create the object:

const keys = ["J", "o", "h", "a", "n"];
const values = [1, 1, 1, 2, 1];

// We are using reduce to iterate over the keys array and create an object
const result = keys.reduce(
  (
acc, // The first argument is the accumulator, which is the object we are building
key, // The second argument is the current value, which is the current key
i // The third argument is the index, which is the current index
  ) => {
// We are returning the accumulator with the current key and value
return {
  ...acc, // We are spreading the accumulator to keep the previous values
  [key]: values[i], // We are adding the current key and value
};
  },
  {} // The second argument for reduce is the initial value, which is an empty object this is used as the first value of the accumulator
);

console.log("result", result);