如何在Golang的循环中删除结构数组的元素？

问题

我有一系列的结构：

type Config struct {
  Applications []Application
}

注意：config-是json.decode的结构。

config = new(Config)
_ = decoder.Decode(&config)

在循环中，我有一些条件和元素按键删除。

for i, application := range config.Applications {
  if i == 1 {
    config.Applications = _removeApplication(i, config.Applications)
  }
}

func _removeApplication(i int, list []Application) []Application {
  if i < len(list)-1 {
    list = append(list[:i], list[i+1:]...)
  } else {
    log.Print(list[i].Name)
    list = list[:i]
  }

  return list
}

但我总是有“超出范围”的错误。从结构数组中按键删除元素的最佳方法是什么？

Quoting from the Slice Tricks page deleting the element at index i:

a = append(a[:i], a[i+1:]...)
// or
a = a[:i+copy(a[i:], a[i+1:])]

Note that if you plan to delete elements from the slice you're currently looping over, that may cause problems. And it does if the element you remove is the current one (or a previous element already looped over) because after the deletion all subsequent elements are shifted, but the range loop does not know about this and will still increment the index and you skip one element.

You can avoid this by using a downward loop:

for i := len(config.Applications) - 1; i >= 0; i-- {
    application := config.Applications[i]
    // Condition to decide if current element has to be deleted:
    if haveToDelete {
        config.Applications = append(config.Applications[:i],
                config.Applications[i+1:]...)
    }
}

You are getting this error because you are doing a loop over a slice with an inital range of X length that became X-n because you remove some elements during loop.

If you want to delete an item at a specific index from a slice, you can do it this way:

sliceA = append(sliceA[:indexOfElementToRemove], sliceA[indexOfElementToRemove+1:]...)

This question is a bit older but I haven't found another answer on StackOverflow which mentions the following trick from the Slice Tricks to filter a list:

b := a[:0]
for _, x := range a {
    if f(x) {
        b = append(b, x)
    }
}

So in this case a function which deletes certain elements could look like this:

func removeApplications(apps []Applications) []Applications {
    filteredApps := apps[:0]
    for _, app := apps {
        if !removeApp {
            filteredApps = append(filteredApps, app)
        }
    }
    return filteredApps
}

I think the simple way is

var (
  slice = []int{1,2,3,4,5}
  pos int
)
    for _, i := range slice {
        if i == 3 {
            slice = append(slice[:pos], slice[pos+1:]...)
            if pos > 0 {
                pos = pos - 1
            }
            continue
        }
        pos++
    }

here is... https://play.golang.org/p/pK3B5Mii9k