不使用make创建Go切片

Question

nums := []int{2, 3, 4}

What does this do in go? Am I creating an array or a slice?

From this: https://gobyexample.com/range, it says slice. But I think it is an array.

Answer 1

In go, array types include their length. Since you omitted the length it is a slice:

array := [3]int{1, 2, 3} // Array since it includes length (3).
slice := array[:] // Slice since there is no length specified.

fmt.Printf("%#v - %T
", slice, slice) // %T means "type".
fmt.Printf("%#v - %T
", array, array)
// [3]int{1, 2, 3} - [3]int
// []int{1, 2, 3} - []int

In the example above, we made a slice without invoking "make" by setting it to the full range of of array. If you were to edit either array or slice then both will change, since "slice" is essentially a view into the storage that is "array".

slice[0] = 456 // And array[0] == 456
array[0] = 789 // And slice[0] == 789