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jolamemushaj
jolamemushaj

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Three ways to iterate an array

Given an array of integers, return a new array with each value doubled.

For example: [2, 4, 6] --> [4, 8, 12]

Number #1: We use a for loop to iterate over the elements, transform each individual one, and push the results into a new array.

function doubleValues(array) {
    let result = [];
    for (let i = 0; i < array.length; i++) {
        result.push(array[i] * 2);
    }
    return result;
}

console.log(doubleValues([1, 2, 3, 4]));
// [2, 4, 6, 8]
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Number #2: For-of loop.

function doubleValues(array) {
    let result = [];
    for (const element of array) {
        result.push(element * 2);
    }
    return result;
}

console.log(doubleValues([1, 2, 3, 4]));
// [2, 4, 6, 8]
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Number #3: JavaScript Array type provides the map() method that allows you to transform the array elements in a cleaner way.

const array = [1, 2, 3, 4];
const doubleValues = array.map(element => element * 2);
console.log(doubleValues);
// [2, 4, 6, 8]
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Top comments (1)

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huykonofficial profile image
Huy Kon

another way
Array.from(array, x => x *2)

Need a better mental model for async/await?

Check out this classic DEV post on the subject.

β­οΈπŸŽ€ JavaScript Visualized: Promises & Async/Await

async await