ForEach vs. Map: Understanding the Key Differences in JavaSc

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Introduction to ForEach and Map
In JavaScript, both forEach and map are used to iterate over arrays. However, they serve different purposes and should be used accordingly for better performance and readability.

What is ForEach?
The forEach method executes a provided function once for each array element. It does not return a new array and is mainly used for side effects, such as modifying elements or logging values to the console foreach vs map.

What is Map?
The map method is used to create a new array by applying a transformation function to each element of the original array. It is ideal when you need to modify data while keeping the original array unchanged.

Key Differences Between ForEach and Map

Return Value: forEach returns undefined, whereas map returns a new array.
Performance: forEach is faster when no new array is needed, while map is efficient for transformations.
Mutability: map is a pure function, leaving the original array intact, whereas forEach can modify it.
When to Use ForEach
Use forEach when performing operations such as updating elements in an existing array, logging values, or making API calls. It is best for executing functions without needing a return value.

When to Use Map
Use map when you need to modify data and store the results in a new array. It is commonly used in functional programming for transformations like formatting strings, filtering data, or converting values.

Conclusion: Choosing the Right Method
Both forEach and map are essential JavaScript functions, but their use cases differ. If you need a transformed array, map is the better choice. If you just need to iterate without modifying the original array, forEach is more suitable.