将数组从索引1发送到函数

Question

I've this function and and I got values which I need to use from args

Run: func(cmd *cobra.Command, args []string) {

   ....

    myFunc(args)
} 

I need to pass to myFunc all the args from index 1 and not 0. of course I can loop and create another array from index 1 but this duplicate almost all the values except index 0 , is there a way to avoid it in GO?

Answer 1

Yes, simply slice the args slice, and pass that:

myFunc(args[1:])

args is a slice, not an array. You can (re-)slice slices, which will be a contiguous subpart of the original slice. For example:

args[1:4]

The above would be another slice, holding only the following elements from args:

args[1], args[2], args[3]

The upper limit is exclusive. A missing upper index defaults to the length, a missing lower index defaults to 0. These are all detailed in Spec: Slice expressions.

Note that slicing a slice does not copy the elements: it will point to the same underlying array which actually holds the elements. A slice is just a small, struct-like header containing a pointer to the underlying array.

Note that if args is empty, the above would result in a run-time panic. To avoid that, first check its length:

if len(args) == 0 {
    myFunc(nil) // or an empty slice: []string{}
} else {
    myFunc(args[1:])
}