Find the depth to which an array is full:

ArrayDepth counts only dimensions at which an expression is not "ragged":

ArrayDepth works with special array types, including SparseArray objects:

SymmetrizedArray objects:

NumericArray objects:

Find the depth of a matrix that is a mixture of List and different special array heads:

ArrayDepth works with any head, not just List:

Length[Dimensions[expr]] equals ArrayDepth[expr]:

ArrayDepth always returns a non-negative integer:

The default value of the option AllowedHeads allows mixtures of list, sparse and structured arrays:

It also allows any single head at successive levels:

The following setting of AllowedHeads imitates the default behavior with respect to list-like arrays:

However, it excludes arbitrary heads:

VectorQ, MatrixQ and ArrayQ effectively use AllowedHeads"ListLike":

The setting AllowedHeads"ListLike" does not include ByteArray and NumericArray:

Combine "ListLike" with the additional heads to allow the combination:

ArrayDepth[Array[h,dims]] gives Length[dims]:

ArrayDepth only considers the levels to which the expression is completely rectangular:

Depth considers the deepest part of an expression:

For completely rectangular expressions, ArrayDepth gives a result one smaller than Depth:

Numeric expressions report array depth based of the structure of their FullForm:

To treat all numeric expressions as scalars, use the setting List or "ListLike" for AllowedHeads: