Fortran i Fortran About the Tutorial Fortran was originally developed by a team at IBM in 1957 for scientific calculations. Later developments made it into a high level programming language. In this tutorial, we will learn the basic concepts of Fortran and its programming code. Audience This tutorial is designed for the readers who wish to learn the basics of Fortran. Prerequisites This tutorial is designed for beginners. A general awareness of computer programming languages is the only prerequisite to make the most of this tutorial. Copyright & Disclaimer Copyright 2017 by Tutorials Point (I) Pvt. Ltd. All the content and graphics published in this e-book are the property of Tutorials Point (I) Pvt. Ltd. The user of this e-book is prohibited to reuse, retain, copy, distribute or republish any contents or a part of contents of this e-book in any manner without written consent of the publisher. 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If you discover any errors on our website or in this tutorial, please notify us at [email protected] i Fortran Table of Contents About the Tutorial ····································································································································i Audience ··················································································································································i Prerequisites ············································································································································i Copyright & Disclaimer ·····························································································································i Table of Contents ···································································································································· ii 1. FORTRAN ─ OVERVIEW ········································································································ 1 Facts about Fortran ·································································································································1 2. FORTRAN ─ ENVIRONMENT SETUP ······················································································ 2 Setting up Fortran in Windows ················································································································2 How to Use G95 ······································································································································3 3. FORTRAN ─ BASIC SYNTAX ··································································································· 4 A Simple Program in Fortran ···················································································································4 Basics ······················································································································································5 Identifier ·················································································································································5 Keywords ················································································································································6 4. FORTRAN ─ DATA TYPES ······································································································ 8 Integer Type ············································································································································8 Real Type ················································································································································9 Complex Type········································································································································ 10 Logical Type ·········································································································································· 11 Character Type ······································································································································ 11 Implicit Typing ······································································································································· 11 ii Fortran 5. FORTRAN ─ VARIABLES ······································································································ 12 Variable Declaration······························································································································ 12 6. FORTRAN ─ CONSTANTS ···································································································· 15 Named Constants and Literals ··············································································································· 15 7. FORTRAN ─ OPERATORS ···································································································· 17 Arithmetic Operators ···························································································································· 17 Relational Operators ····························································································································· 19 Logical Operators ·································································································································· 21 Operators Precedence in Fortran ·········································································································· 23 8. FORTRAN ─ DECISIONS ······································································································ 26 If…then Construct ································································································································· 27 If… then… else Construct ······················································································································· 29 if...else if...else Statement ····················································································································· 31 Nested If Construct ······························································································································· 33 Select Case Construct ···························································································································· 34 Nested Select Case Construct ················································································································ 37 9. FORTRAN ─ LOOPS············································································································· 39 do Loop ················································································································································· 40 do-while Loop ······································································································································· 43 Nested Loops ········································································································································ 45 Loop Control Statements······················································································································· 46 Exit Statement ······································································································································ 47 Cycle Statement ···································································································································· 48 Stop Statement ····································································································································· 50 iii Fortran 10. FORTRAN ─ NUMBERS ······································································································· 51 Integer Type ·········································································································································· 51 Real Type ·············································································································································· 52 Complex Type········································································································································ 53 The Range, Precision, and Size of Numbers ··························································································· 55 The Kind Specifier ································································································································· 57 11. FORTRAN ─ CHARACTERS ·································································································· 59 Character Declaration ··························································································································· 59 Concatenation of Characters ················································································································· 60 Some Character Functions ····················································································································· 61 Checking