Learn Fortran - 10 Code Examples & CST Typing Practice Test

Fortran (Formula Translation) is a high-level, compiled programming language designed for numeric computation, scientific computing, and engineering applications. Known for its efficiency in numerical calculations, Fortran has been a standard in scientific computing for over 60 years.

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Fortran Counter and Theme Toggle Fortran Simple Addition Fortran Factorial Fortran Fibonacci Sequence Fortran Max of Two Numbers Fortran Array Sum Fortran Even Numbers Filter Fortran Conditional Counter Increment Fortran Resettable Counter Fortran Theme Toggle Only

Learn FORTRAN with Real Code Examples

Updated Nov 20, 2025

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Code Sample Descriptions

Fortran Counter and Theme Toggle

program Counter
    integer :: count = 0
    logical :: isDark = .false.

    print *, 'Counter:', count
    print *, 'Theme:', merge('Dark','Light',isDark)

    ! Increment counter
    count = count + 1
    print *, 'Counter:', count

    ! Toggle theme
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)

    ! Decrement counter
    count = count - 1
    print *, 'Counter:', count

    ! Reset counter
    count = 0
    print *, 'Counter:', count
end program Counter

Demonstrates a simple counter with theme toggling using Fortran variables and console output.

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Fortran Simple Addition

program Addition
    integer :: a = 10
    integer :: b = 20
    integer :: sum
    sum = a + b
    print *, 'Sum:', sum
end program Addition

Adds two numbers and prints the result.

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Fortran Factorial

program Factorial
    integer :: fact = 1
    integer :: i
    for i = 1, 5
        fact = fact * i
    end for
    print *, 'Factorial:', fact
end program Factorial

Calculates factorial of 5 using a loop.

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Fortran Fibonacci Sequence

program Fibonacci
    integer :: fib0 = 0, fib1 = 1, next, i
    print *, fib0
    print *, fib1
    do i = 3, 10
        next = fib0 + fib1
        print *, next
        fib0 = fib1
        fib1 = next
    end do
end program Fibonacci

Generates first 10 Fibonacci numbers.

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Fortran Max of Two Numbers

program MaxNumber
    integer :: a = 15, b = 25, max
    if (a > b) then
        max = a
    else
        max = b
    end if
    print *, 'Max:', max
end program MaxNumber

Finds the maximum of two numbers.

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Fortran Array Sum

program ArraySum
    integer, dimension(5) :: nums = (/1,2,3,4,5/)
    integer :: sum = 0, i
    do i = 1, 5
        sum = sum + nums(i)
    end do
    print *, 'Sum:', sum
end program ArraySum

Sums elements of an array.

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Fortran Even Numbers Filter

program EvenFilter
    integer, dimension(5) :: nums = (/1,2,3,4,5/)
    integer :: i
    do i = 1, 5
        if (mod(nums(i),2) == 0) then
        print *, 'Even:', nums(i)
        end if
    end do
end program EvenFilter

Prints even numbers from an array.

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Fortran Conditional Counter Increment

program ConditionalIncrement
    integer :: count = 3
    if (count < 5) then
        count = count + 1
    end if
    print *, 'Count:', count
end program ConditionalIncrement

Increment counter only if less than 5.

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Fortran Resettable Counter

program ResettableCounter
    integer :: count = 0
    count = count + 1
    count = count + 1
    count = count + 1
    print *, 'Count:', count
    count = 0
    print *, 'Count after reset:', count
end program ResettableCounter

Counter that increments and can be reset.

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Fortran Theme Toggle Only

program ThemeToggle
    logical :: isDark = .false.
    print *, 'Theme:', merge('Dark','Light',isDark)
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)
end program ThemeToggle

Toggles theme multiple times.

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Frequently Asked Questions about Fortran

What is Fortran?

What are the primary use cases for Fortran?

Scientific simulations. Numerical and matrix computations. High-performance computing. Weather & climate modeling. Finite element analysis. Computational physics & chemistry

What are the strengths of Fortran?

High computational performance. Mature ecosystem in scientific computing. Efficient memory and vectorized operations. Widely supported in HPC systems. Legacy codebases in critical scientific domains

What are the limitations of Fortran?

Primarily numerical, not general-purpose. Older syntax can be verbose. Limited libraries for modern tasks outside science. Cross-platform GUIs are weak. Complex parallel programming setup

How can I practice Fortran typing speed?

CodeSpeedTest offers 10+ real Fortran code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

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Code Sample Descriptions

Fortran Counter and Theme Toggle

program Counter
    integer :: count = 0
    logical :: isDark = .false.

    print *, 'Counter:', count
    print *, 'Theme:', merge('Dark','Light',isDark)

    ! Increment counter
    count = count + 1
    print *, 'Counter:', count

    ! Toggle theme
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)

    ! Decrement counter
    count = count - 1
    print *, 'Counter:', count

    ! Reset counter
    count = 0
    print *, 'Counter:', count
end program Counter

Demonstrates a simple counter with theme toggling using Fortran variables and console output.

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Fortran Simple Addition

program Addition
    integer :: a = 10
    integer :: b = 20
    integer :: sum
    sum = a + b
    print *, 'Sum:', sum
end program Addition

Adds two numbers and prints the result.

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Fortran Factorial

program Factorial
    integer :: fact = 1
    integer :: i
    for i = 1, 5
        fact = fact * i
    end for
    print *, 'Factorial:', fact
end program Factorial

Calculates factorial of 5 using a loop.

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Fortran Fibonacci Sequence

program Fibonacci
    integer :: fib0 = 0, fib1 = 1, next, i
    print *, fib0
    print *, fib1
    do i = 3, 10
        next = fib0 + fib1
        print *, next
        fib0 = fib1
        fib1 = next
    end do
end program Fibonacci

Generates first 10 Fibonacci numbers.

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Fortran Max of Two Numbers

program MaxNumber
    integer :: a = 15, b = 25, max
    if (a > b) then
        max = a
    else
        max = b
    end if
    print *, 'Max:', max
end program MaxNumber

Finds the maximum of two numbers.

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Fortran Array Sum

program ArraySum
    integer, dimension(5) :: nums = (/1,2,3,4,5/)
    integer :: sum = 0, i
    do i = 1, 5
        sum = sum + nums(i)
    end do
    print *, 'Sum:', sum
end program ArraySum

Sums elements of an array.

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Fortran Even Numbers Filter

program EvenFilter
    integer, dimension(5) :: nums = (/1,2,3,4,5/)
    integer :: i
    do i = 1, 5
        if (mod(nums(i),2) == 0) then
        print *, 'Even:', nums(i)
        end if
    end do
end program EvenFilter

Prints even numbers from an array.

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Fortran Conditional Counter Increment

program ConditionalIncrement
    integer :: count = 3
    if (count < 5) then
        count = count + 1
    end if
    print *, 'Count:', count
end program ConditionalIncrement

Increment counter only if less than 5.

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Fortran Resettable Counter

program ResettableCounter
    integer :: count = 0
    count = count + 1
    count = count + 1
    count = count + 1
    print *, 'Count:', count
    count = 0
    print *, 'Count after reset:', count
end program ResettableCounter

Counter that increments and can be reset.

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Fortran Theme Toggle Only

program ThemeToggle
    logical :: isDark = .false.
    print *, 'Theme:', merge('Dark','Light',isDark)
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)
    isDark = .not. isDark
    print *, 'Theme:', merge('Dark','Light',isDark)
end program ThemeToggle

Toggles theme multiple times.

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Frequently Asked Questions about Fortran

What is Fortran?

What are the primary use cases for Fortran?

Scientific simulations. Numerical and matrix computations. High-performance computing. Weather & climate modeling. Finite element analysis. Computational physics & chemistry

What are the strengths of Fortran?

High computational performance. Mature ecosystem in scientific computing. Efficient memory and vectorized operations. Widely supported in HPC systems. Legacy codebases in critical scientific domains

What are the limitations of Fortran?

Primarily numerical, not general-purpose. Older syntax can be verbose. Limited libraries for modern tasks outside science. Cross-platform GUIs are weak. Complex parallel programming setup

How can I practice Fortran typing speed?

CodeSpeedTest offers 10+ real Fortran code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.