切片数组-GO

Question

1)

For below slice declaration,

var a [][3]string

creates a single slice(a) that points to array of 3 strings, len(a) = 3 and cap(a) =3 but not cap(a) >= 3

a = make([][3]string, 5)

creates 5 slices, where each slice(say a[0]) points to array of 3 strings, len(a[0]) = 3 and cap(a[0]) = 3

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2)

For slice declaration,

var b [][3][6]string

creates a single slice(b) that points to 3 arrays of 6 strings each, where len(b) = 3 and cap(b) =3

b = make([][3][6]string, 5)

creates 5 slices, where each slice(say b[0]) points to 3 arrays of 6 strings each

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In both cases, after making slices, I said, creates 5 slices,

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Considering the syntax, below are my two questions,

a = make([][3]string, 5)

My question:

1)

Is it 5 slices, where each slice(a[0]) is array of 3 strings?

or

Is it a single slice(a) pointing to 5 arrays of 3 strings each?

2)

How do I know the type of an element? slice or array?

1) In such scenarios, "array of" terminology has to be cautiously used.

2) There are no implicit pointers involved in GO unlike C

Answer 1

1) Considering the syntax,

a = make([][3]string, 5)

Is it 5 slices, where each slice(a[0]) is array of 3 strings?

or

Is it a single slice(a) pointing to 5 arrays of 3 strings each?

Its a single slice with 5 elements where each element is an array of 3 strings.

2)

How do I know the type of an element? slice or array?

Slices and arrays are different types. You can not interchangeably assign arrays and slices to the same variable, hence if the declaration declares it as an array, its an array, if it declares it as a slice, its a slice. If it has a number in the brackets ([5]string) its an array, if the brackets are empty ([]string) its a slice.

2) For slice declaration,

var b [][3][6]string

creates a single slice(b) that points to 3 arrays of 6 strings each, where len(b) = 3 and cap(b) =3

b = make([][3][6]string, 5)

creates 5 slices, where each slice(say b[0]) points to 3 arrays of 6 strings each

No. Former code just declares a variable, it doesn't hold a slice yet. Latter code creates one slice with five elements.