Fortran 90 Features

Here is a list of some features that I found useful. And some differences from Fortran 77. As well as some tricks and techniques.
Look and Feel
New, improved source format - no more 72 character limit
Variable declarations - more options and flexibility

Loops and Conditionals
New power for old do loops and if statements
Plus a case statement - clean up those ugly if-then-else chains

Dynamic memory allocation
Allocate what you need at run time - no more recompiling when you need larger arrays.
And pointers. Now you too can create linked lists and trees.

Array operations
Operate on arrays as easily as scalars

Derived data types
Do-it-yourself data types - similar to C structures

Overloaded operators
Add even more power to derived data types

Combine data and subprograms in one chunk. Great for global data, private data, simple object oriented programming, and more.
The book I have been using is Migrating to Fortran 90 by James F. Kerrigan.

Here's a partial list of intrinsic functions and subroutines.

One downside of all these great new features can be perfomance problems, particularly when passing dynamic arrays into subroutines.

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