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Mis juhtub, kui lisame funktsiooni sees liiga palju elemente slice'ile?

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Vastus AI-lt

In Go, a slice is a structure that contains a pointer to an array, a length, and a capacity. If you add too many elements to a slice, exceeding its current capacity, Go will automatically allocate a new larger array and copy the data there.

This means that when adding elements, the slice can be reallocated, which incurs additional time and memory costs. If you add elements to a slice inside a function without returning a new slice, the changes may not be saved, as the slice is passed by value (the structure is copied, but not the data).

Example:

func appendElements(s []int) {
    for i := 0; i < 1000; i++ {
        s = append(s, i) // a new slice is created when capacity is exceeded
    }
}

// To keep the changes, you need to return the slice:
func appendElementsCorrect(s []int) []int {
    for i := 0; i < 1000; i++ {
        s = append(s, i)
    }
    return s
}

Therefore, when adding a large number of elements, it is important to consider memory reallocation and work correctly with the returned slice value.