When to defer in Go

I wrote a simple program that calls a site repeatedly.

I borrowed the example from https://mholt.github.io/curl-to-go/

Then the program crashed when the target site was not available.

The original code:

resp, err := http.Get(url)
if err != nil {
    // handling
    time.Sleep(600)
}
defer resp.Body.Close()

When res is null, defer doesn’t work.

The better code:

resp, err := http.Get(url)
if resp != nil {
    defer res.Body.Close()
}
if err != nil {
    // handling
    continue;
}