How Can I Modify a Slice in a Go Function Without Affecting the Original?

Modify a Slice Passed to a Function

In Go, parameters are passed by value, which means that changes made to a slice within a function do not affect the original slice. This can pose a problem when using recursive functions, where you want to modify the accumulator slice.

Passing a Pointer to the Slice

To modify the original slice, you can pass a pointer to the slice as a function parameter. This allows the function to modify the original slice through the pointer.

For example:

func myAppend(list *[]string, value string) {
    *list = append(*list, value)
}

Updated Solution

Instead of passing a pointer to the slice, you can return the modified slice from the recursive function. This allows the function to accumulate the values in the slice and return the final result to the caller.

func validate(obj Validatable, messages []ValidationMessage) ([]ValidationMessage, error) {
    // ...

    return validate(v, messages)
}

Idiomatic Approach

Passing a pointer to the slice or returning the modified slice are both idiomatic approaches in Go. The choice of which approach to use depends on the specific requirements of your function.

Note:

When using pointers to modify slices, it's important to ensure that the pointers are not nil and that the slices are not modified concurrently.

The above is the detailed content of How Can I Modify a Slice in a Go Function Without Affecting the Original?. For more information, please follow other related articles on the PHP Chinese website!