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What’s the difference between map() and forEach() when looping through arrays?

Asked on Sep 25, 2025

Answer

The "map()" and "forEach()" methods both iterate over arrays, but they serve different purposes: "map()" transforms each element and returns a new array, while "forEach()" executes a function for each element without returning a new array.

// Using map()
        const numbers = [1, 2, 3];
        const doubled = numbers.map(num => num * 2);
        console.log(doubled); // Output: [2, 4, 6]

        // Using forEach()
        const numbers = [1, 2, 3];
        numbers.forEach(num => console.log(num * 2));
        // Output: 2
        // Output: 4
        // Output: 6

Additional Comment:

"map()" creates a new array with the results of calling a provided function on every element.
"forEach()" executes a provided function once for each array element but does not return a new array.
Use "map()" when you need to transform data and use "forEach()" for side effects like logging or updating external variables.

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Ask any question about JavaScript here... and get an instant response.

What’s the difference between map() and forEach() when looping through arrays?

Asked on Sep 25, 2025

Answer

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