FORTRAN Reference Manual

Introduction to File I/O in the HP NonStop

Environment

FORTRAN Reference Manual—528615-001

5-27

Using Implied DO Lists

An implied DO list has the following form:

( [(]... ar-nam1( var1 [, var2 ]... )

[, ar-nam2( var1 [, var2 ]... ) ]... ,

var1 = iexp1, fexp1°[, incr1 ] )

[, var2 = iexp2, fexp2°[, incr2°] ) ]...

ar-name

is the name of an array.

var

is an integer, real, or double precision control variable. It must be a simple variable,

not an array element or a RECORD component.

iexp

is an expression that specifies the initial value of each var.

fexp

is an expression that specifies the final value of each var.

incr

is an expression that specifies the increment value of each var. The default value

for incr is 1.

You can specify a DO list both in DATA statements and in data transfer statements.

The following example uses an implied DO list to initialize the array INVENTORY to 0:

DATA (inventory(i), i = 1, 25) / 25 * 0 /

You can use an implied DO list to initialize partial arrays. For example, the following

DATA statement initializes the first 10 elements and the last 10 elements of the array

PAY(30) to 0:

INTEGER pay(30)

DATA (pay(k), k = 1,10), (pay(k), k = 21,30) /20 * 0/

You can read the elements of multidimensional arrays using an implied DO list. For

example, the following READ statement reads all elements of the two-dimensional

array A:

INTEGER a(2, 4)

READ(10,100) ((a(i,j), i = 1,2), j = 1,4)