Why Does Modifying Values Using Go's `range` Keyword Fail, and How Can Array Indices Provide a Solution?

The Usage of Array Indices over Range Values

When utilizing the range keyword with arrays or slices in Go, it's essential to understand that it returns the key and a copy of the value, not the original value reference. This behavior can lead to confusion when attempting to modify values within the collection during iteration.

In the example provided:

It's expected that the range iteration assigns the string "foo" to the field of each element in the array. However, when the second loop prints the updated values, all fields remain empty. This is due to the copy-based semantics of range.

To effectively modify the values within the array during iteration, it's necessary to use the array index instead of the range variable:

This modification ensures that the index variable references the actual element in the array, allowing for proper field updates and correct output in the second loop.

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