Take a look at ``array1.f'' in your ``examples'' directory (or view it directly). This program prompts the user for and reads ten numbers, and then prints them all back out. What is clumsy about this program?
The program cries out to be simplified by using a DO loop to repeat the statements
PRINT *, 'Please enter an integer' READ *, N1
ten times over, and by using another DO loop to repeat the statement
PRINT *, N1
ten times over. Unfortunately, this is not possible (at least without arrays!). Why not?
By using an array of ten elements to store the input, instead of ten distinct variables, we can vastly shorten the program. Take a look at ``array2.f'' (or view it directly).
This program is very similar to the first version. What are the differences?
Now it is possible to shorten this program by using a DO loop. Take a look at ``array3.f'' (or view it directly). What have we done to take advantage of arrays?
Does this convince you of the utility of arrays? If not, consider what changes would be required for ``array1.f'' if you wanted to read 100 numbers. Compare that to the changes required for ``array3.f'' to accomplish the same thing.
Hamlet Project