Declarations

So long as the value of lda is known, the following are valid:

    REAL, DIMENSION(100)       :: A
    REAL, DIMENSION(10,10)     :: B
    REAL, DIMENSION(-10:-1)    :: X
    INTEGER, PARAMETER :: lda = 5
    REAL, DIMENSION(0:lda-1)   :: Y
    REAL, DIMENSION(1+lda*lda,10) :: Z

The above example demonstrates:

• bounds can begin and end anywhere, (the array X),
• default lower bound is 1, (the second dimension of Z),
• arrays can be zero-sized. If lda were set to be zero,

      INTEGER, PARAMETER :: lda = 0

  then the array Y would be zero sized.

  Zero-sized arrays are useful when programming degenerate cases especially when invoking procedures (in this case we would expect lda to be a dummy argument which determines the size of some local (or automatic) array); no extra code has to be added to test for zero extents in any of the dimensions -- statements including references to zero sized arrays are simply ignored.

Now try this question