Using array methods, retrieve every alternate element from the array

Question

Using array methods, retrieve every alternate element from the array

As part of my learning journey, I successfully extracted every second element from an array using a for loop:

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

  function filterEverySecond(arr) {
    let everySecondEl = [];
    for (let i = 0; i < arr.length; i += 2) {
      everySecondEl.push(arr[i]);
    }
    return everySecondEl;
  }

  console.log({
    numbers,
    result: filterEverySecond(numbers)
  });

Now, I am looking to achieve the same outcome without using a for loop, but instead by utilizing array methods such as forEach, filter, map, or reduce. Would appreciate some recommendations on which method would be most suitable for this scenario.

javascript arrays

Answer 1

Answer №1

It's a breeze with the power of filter

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

const filtered = numbers.filter((_, i) => i % 2 === 0)

console.log(filtered)

Simply exclude the elements with an odd index

Answer 2

It's a breeze with the power of filter

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

const filtered = numbers.filter((_, i) => i % 2 === 0)

console.log(filtered)

Simply exclude the elements with an odd index

Answer 3

Answer №2

To filter out elements from an array based on the index being divisible by 2, you can use the `filter` method:

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

console.log({
  numbers,
  result: numbers.filter((_, index) => index % 2 === 0)
});

Answer 4

To filter out elements from an array based on the index being divisible by 2, you can use the `filter` method:

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

console.log({
  numbers,
  result: numbers.filter((_, index) => index % 2 === 0)
});

Answer 5

Answer №3

If you want to filter based on index, use the filter method.

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
console.log({
    numbers,
    filteredNumbers: numbers.filter((num, index) => index % 2 === 0)
});

Answer 6

If you want to filter based on index, use the filter method.

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
console.log({
    numbers,
    filteredNumbers: numbers.filter((num, index) => index % 2 === 0)
});

Answer 7

Answer №4

To achieve the desired result, you can utilize a for each loop in the following manner:

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const result = [];

numbers.forEach(number => {
    if (number % 2 != 0) {
        result.push(number);
    }
});

console.log(numbers);
console.log(result);

The modulus operator calculates the remainder of division between two numbers. For instance: 1 % 2 will give a result of 1 as the remainder. Therefore, in the if statement, we are verifying if the number is not divisible by 2.

Answer 8

To achieve the desired result, you can utilize a for each loop in the following manner:

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const result = [];

numbers.forEach(number => {
    if (number % 2 != 0) {
        result.push(number);
    }
});

console.log(numbers);
console.log(result);

The modulus operator calculates the remainder of division between two numbers. For instance: 1 % 2 will give a result of 1 as the remainder. Therefore, in the if statement, we are verifying if the number is not divisible by 2.

Using array methods, retrieve every alternate element from the array

Answer №1

Answer №2

Answer №3

Answer №4

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