Append to a slice inside a range loop

[Frank Blechschmidt]

Hey!

Is it possible to append to a slice/array inside a loop and keep the changes after leaving the loop?

Example:

result[][]string //filled array with entries from a database

result2[][]string //filled array with additional information for database entries

for i, entry := range result {

entry = append(entry, result2[i][1])

fmt.Println("i: ", i)

fmt.Println("entry: ", entry)

}

fmt.Println("Final result", result)

When I print the entry inside them loop, it looks like how I want it.

When I print the final result, all appended data is lost.

Beste regards

Frank

[steve wang]

The only thing you need to do is to put back the resized slice.

for i, entry := range result {

entry = append(entry, result2[i][1])

        result[i] = entry     // <=======

fmt.Println("i: ", i)

fmt.Println("entry: ", entry)

}

[Frank Blechschmidt]

Thanks, man :)

[matt]

Wouldn't this be more idiomatic as

for i, _ := range result {

result[i] = append(result[i], result2[i][1])

fmt.Printf("[%d] entry: %s\n", i, result[i])

[David DENG]

This is anyway better:

for i := range result {

result[i] = append(result[i], result2[i][1])

fmt.Printf("[%d] entry: %s\n", i, result[i])

}

David

[Dave Cheney]

In Go 1.1, the former is rewritten by the compiler to be identical to
your example.

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[Nate Finch]

Awesome. :)

On Friday, March 15, 2013 10:07:56 AM UTC-4, Dave Cheney wrote:

In Go 1.1, the former is rewritten by the compiler to be identical to
your example.

On Fri, Mar 15, 2013 at 8:52 PM, David DENG <david...@gmail.com> wrote:
> This is anyway better:
>
> for i := range result {
>