The Essential Guide to Fortran Interview Questions for Programmers

Ask the right questions to secure the right Fortran talent among an increasingly shrinking pool of talent.

Fortran, which stands for “Formula Translation,” is a high-level programming language that was created by IBM in the 1950s. It is one of the oldest computer languages that is still used today. It was designed for scientific and engineering computations due to its ability to handle complex numerical calculations. The language revolutionized software development and set a precedent for future programming languages like ALGOL and COBOL. Fortran has stayed useful for a long time because it is always getting better. The most recent version, Fortran 2018, was released by ISO/IEC. Its historical significance and ongoing utility make it a cornerstone in the field of computer programming.

The next twenty minutes of the interview should try to get more specific about the development questions that were asked and how knowledgeable and skilled the engineer is.

When interviewing someone for a job in Fortran, the last few questions should usually be about a mix of technical skills, personal goals, growth potential, team dynamics, and company culture.

Fortran is one of the oldest programming languages still widely used today. Originally developed by IBM in 1957 for scientific and engineering applications, Fortran revolutionized software development and set the stage for other influential languages like COBOL and ALGOL.

Even after over 60 years, Fortran continues to be popular in fields like weather prediction, physics simulations, and numeric modeling thanks to its efficient computation abilities. This enduring relevance means that Fortran skills remain in demand, especially for scientific programming roles.

So whether you’re a programmer looking to ace an interview or a hiring manager seeking the perfect Fortran developer, having a solid grasp of common Fortran interview questions is key. In this comprehensive guide, I’ll cover the top Fortran interview questions frequently asked by employers and provide pointers to formulate strong answers.

Let’s get started!

Overview of Key Fortran Interview Topics

Here are some of the most common categories of Fortran interview questions you’re likely to encounter

General Fortran Knowledge: Syntax, data types, variable declarations, loops, conditional statements
Arrays and Matrices: Declaration, manipulation, operations
Functions and Subroutines: Differences, parameters, return values
File I/O: Opening, reading, writing, closing files
Program Structure: Modules, derived types, encapsulation
Memory Allocation: Static vs dynamic allocation
Parallel Programming: Using OpenMP, MPI, concurrent programming
Numeric Computing: Solving linear systems, Monte Carlo simulations
Debugging and Testing: Techniques for finding and fixing errors
Language Standards: Differences between Fortran 77, 90, 95, etc.

I’ll provide example questions for each of these topics in the following sections.

General Fortran Interview Questions

These fundamental Fortran interview questions assess your basic language familiarity:

Q: What are the different data types supported in Fortran?

Integer, real, complex, logical, character

Q How do you declare a variable in Fortran?

Using the type keyword e.g. integer :: x

Q: What is the purpose of the implicit none statement?

Enforces explicit declarations and avoids errors from implicit typing

Q: How do you write conditional statements like if-else in Fortran?

Using if (condition) then, else if, else constructs

Q: Explain the syntax of do loops in Fortran.

do i = 1, 10, end do

Q: What are some intrinsic functions in Fortran?

SQRT, SIN, COS, LOG, EXP, MAX, MIN

Questions on Arrays and Matrices

Since Fortran is used extensively for mathematical computing, expect questions on handling arrays and matrices:

Q: How do you declare a multidimensional array in Fortran?

integer, dimension(5,5) :: my_matrix

Q: How do you access and modify individual elements of an array?

Using bracket subscript notation like my_array(2,3)

Q: What are some built-in array manipulation functions in Fortran?

SUM, PRODUCT, MAXVAL, MINVAL, SHAPE, RESHAPE

Q: How can you perform operations on entire arrays without loops?

Using whole array expressions like C = A + B

Fortran Function and Subroutine Questions

Functions and subroutines are used extensively in Fortran for modularity. Interviewers may ask:

Q: What is the difference between a function and subroutine in Fortran?

Functions return values which can be used in expressions, while subroutines do not return values.

Q: How do you pass arguments to subroutines and functions?

Through positional arguments or keyword arguments for clarity

Q: What is the purpose of the bind(c) attribute for subprograms?

Allows interoperability with C code

Q: How do you return a value from a function in Fortran?

Using the return statement, specifying the return variable

File Input/Output Questions

File I/O is a common task in Fortran programming. You may be asked:

Q: How do you open and close a file in Fortran?

Using open and close statements

Q: What mode specifiers can you use with open?

read, write, append, etc.

Q: How do you read from and write to a file in Fortran?

read and write statements

Q: How can you check for errors in file handling?

Using the iostat specifier to get error codes

Fortran Program Structure Questions

Since Fortran supports modular programming, expect questions like:

Q: What is the purpose of modules in Fortran?

Allows encapsulation of procedures, data, types

Q: How do you define a derived data type in Fortran?

Using type and end type statements

Q: What are some advantages of using derived types?

Enables custom data structures, bundling data with procedures

Q: How do you restrict access to module components?

Using private attribute for information hiding

Memory Allocation Interview Questions

Memory handling is important for optimal performance:

Q: What is the difference between static and dynamic allocation in Fortran?

Static at compile time vs dynamic at runtime

Q: How do you dynamically allocate memory in Fortran?

Using allocate and deallocate on allocatable arrays

Q: What is the advantage of dynamic over static allocation?

Flexibility to adjust memory as needed during execution

Q: What is the save attribute used for in Fortran?

Retains local variable values between calls to a procedure

Parallel Programming Questions

With parallel hardware ubiquitous, expect questions like:

Q: How can you implement parallel programming in Fortran?

Using OpenMP directives or MPI library

Q: What OpenMP directive parallelizes a do loop?

!$omp parallel do

Q: What is the purpose of reductions in OpenMP?

Efficiently combines values from threads

Q: How does MPI help in distributed parallel programming?

Has functions for passing messages between processes

Numeric Programming Interview Questions

Since Fortran excels at numerical computing, be ready for:

Q: How would you solve a system of linear equations in Fortran?

Using LAPACK routines like gesv

Q: How can you implement a Monte Carlo simulation in Fortran?

Generate random numbers and aggregate results over iterations

Q: What intrinsic functions are useful for simulations?

random_number, random_seed

Q: What numerical libraries are commonly used with Fortran?

BLAS, LAPACK, FFTW

Debugging and Testing Questions

Debugging skills are valued in candidates:

Q: What techniques do you use for debugging Fortran programs?

Print debugging, using a debugger, adding assertions

Q: How do you handle exceptions and errors in Fortran code?

error stop statement, error handling subroutines

Q: What best practices do you follow for writing testable code?

Modularity, avoiding side effects, isolating dependencies

Q: What tools exist for unit testing Fortran code?

pFUnit, FRUIT, FUnit

Fortran Standards Questions

Familiarity with different Fortran standards indicates awareness of progress:

Q: What major features were added in Fortran 90/95?

Free form code, modules, dynamic memory, OOP features

Q: How does Fortran 2003 differ from Fortran 95?

Stronger OOP support, abstract interfaces, IEEE floating point

Q: What recent additions were made in Fortran 2018?

Submodules, concurrent programming features

Q: Why is backward compatibility important in Fortran standards?

Allows existing code to work without modifications

Tips for Answering Fortran Interview Questions

Here are some tips to help you formulate strong responses to Fortran interview questions:

Use relevant technical terms and syntax in your responses rather than plain English
Provide concise yet comprehensive answers without rambling
Give examples if asked or where appropriate to illustrate your answer
Highlight your hands-on experience applying Fortran concepts
Mention any specialized domains where you’ve used Fortran
Bring up projects, research, or coursework that utilized Fortran
Compare and contrast related concepts like static vs dynamic memory
Emphasize your debugging skills and how you write robust code
Show enthusiasm for the language and your drive to stay updated

Putting It All Together

In this

How would you handle file input/output in Fortran?

File input/output in Fortran is handled using the open, read, write, and close statements. You can open a file with the open statement, read from and write to the file with read and write, and close the file with close.

The ideal back-end app developer

At this point, a good Fortran engineer should show that they know a lot about the language, including its advanced features and how to fix bugs. They should also show proficiency in numerical computation methods and handling large data sets. Red flags include not being able to solve problems, not being able to clearly explain complicated ideas, and not being familiar with modern Fortran standards.

These will help you see the candidates real-world development capabilities with Fortran.

Fortran Programmer interview questions

FAQ

What is the main purpose of FORTRAN?

Fortran is designed primarily for numerical calculations, and it has many built-in functions for mathematical operations. In the example triangle-area program, we use the basic functions: +, -, *, / for addition, subtraction, multiplication, and division.

What is the first line of every FORTRAN program?

The first statement of this program begins with the word PROGRAM. This is a nonexecutable statement that specifies the name of the program to the FORTRAN compiler. The name may be up to 31 characters long and be any combination of alphabetic characters, digits, and the underscore.

What types of processing is FORTRAN language best suited for?

Fortran (/ˈfɔːrtræn/; formerly FORTRAN) is a third generation, compiled, imperative programming language that is especially suited to numeric computation and scientific computing.

Why is FORTRAN significant?

FORTRAN, computer programming language created in 1957 by John Backus that shortened the process of programming and made computer programming more accessible. The creation of FORTRAN, which debuted in 1957, marked a significant stage in the development of computer programming languages.