There are multiple ways to populate an array.
'one-dimensional
Dim arrayDirect1D(2) As String
arrayDirect(0) = "A"
arrayDirect(1) = "B"
arrayDirect(2) = "C"
'multi-dimensional (in this case 3D)
Dim arrayDirectMulti(1, 1, 2)
arrayDirectMulti(0, 0, 0) = "A"
arrayDirectMulti(0, 0, 1) = "B"
arrayDirectMulti(0, 0, 2) = "C"
arrayDirectMulti(0, 1, 0) = "D"
'...
'one-dimensional only
Dim array1D As Variant 'has to be type variant
array1D = Array(1, 2, "A")
'-> array1D(0) = 1, array1D(1) = 2, array1D(2) = "A"
Dim arrayRange As Variant 'has to be type variant
'putting ranges in an array always creates a 2D array (even if only 1 row or column)
'starting at 1 and not 0, first dimension is the row and the second the column
arrayRange = Range("A1:C10").Value
'-> arrayRange(1,1) = value in A1
'-> arrayRange(1,2) = value in B1
'-> arrayRange(5,3) = value in C5
'...
'Yoo can get an one-dimensional array from a range (row or column)
'by using the worksheet functions index and transpose:
'one row from range into 1D-Array:
arrayRange = Application.WorksheetFunction.Index(Range("A1:C10").Value, 3, 0)
'-> row 3 of range into 1D-Array
'-> arrayRange(1) = value in A3, arrayRange(2) = value in B3, arrayRange(3) = value in C3
'one column into 1D-Array:
'limited to 65536 rows in the column, reason: limit of .Transpose
arrayRange = Application.WorksheetFunction.Index( _
Application.WorksheetFunction.Transpose(Range("A1:C10").Value), 2, 0)
'-> column 2 of range into 1D-Array
'-> arrayRange(1) = value in B1, arrayRange(2) = value in B2, arrayRange(3) = value in B3
'...
'By using Evaluate() - shorthand [] - you can transfer the
'range to an array and change the values at the same time.
'This is equivalent to an array formula in the sheet:
arrayRange = [(A1:C10*3)]
arrayRange = [(A1:C10&"_test")]
arrayRange = [(A1:B10*C1:C10)]
'...
Dim array2D As Variant
'[] ist a shorthand for evaluate()
'Arrays defined with evaluate start at 1 not 0
array2D = [{"1A","1B","1C";"2A","2B","3B"}]
'-> array2D(1,1) = "1A", array2D(1,2) = "1B", array2D(2,1) = "2A" ...
'if you want to use a string to fill the 2D-Array:
Dim strValues As String
strValues = "{""1A"",""1B"",""1C"";""2A"",""2B"",""2C""}"
array2D = Evaluate(strValues)
Dim arraySplit As Variant 'has to be type variant
arraySplit = Split("a,b,c", ",")
'-> arraySplit(0) = "a", arraySplit(1) = "b", arraySplit(2) = "c"