Julia Syntax: Comparison with Fortran

program my_program
    ...
end program

function my_program()
    ...
end
my_program()

module my_module
    ...
end module my_module

module MyModule
    ...
end

subroutine my_subroutine
    ...
end subroutine my_subroutine

function my_subroutine!
    ...
end

function f(x) result(res)
    res = ...
end function f

function my_function(x)
    ...
    return res
end

module cube_root_functions
interface cube_root
    function s_cube_root(x)
      real :: s_cube_root
      real, intent(in) :: x
    end function s_cube_root
    function d_cube_root(x)
      double precision :: d_cube_root
      double precision, intent(in) :: x
    end function d_cube_root
  end interface
end module cube_root_functions
function s_cube_root(x)
    real :: s_cube_root
    real, intent(in) :: x
    s_cube_root = x ** (1.0/3.0)
end function s_cube_root
function d_cube_root(x)
    double precision :: d_cube_root
    double precision, intent(in) :: x
    d_cube_root = x ** (1.0d0/3.0d0)
end function d_cube_root

cube_root( x :: Float32 ) :: Float32 = x^(1/3)
cube_root( x :: Float64 ) :: Float64 = x^(1/3)

module main_module
    ...
contains
<submodule statements>
end module main_module

module MainModule
    ...
    module SubModule 
        ...
    end
end

use my_module
use my_module, only : fun1, var1

using MyModule
import MyModule: fun1, var1

call my_subroutine(args)
my_function(args)

my_function(args)

stop

exit()

! This is a comment

# This is a comment

include 'source_file_name'

include("source_file_name")

if <logical expr> then
    ...
else if <logical expr> then
    ...
else
    ...
end if

if <logical expr>
    ...
elseif <logical expr>
    ...
else
    ...
end

select case <expr>
    case <value>
        ...
    case <value>
        ...
    case default
        ...
end select

 ? : 

function case(x)
    x == 1     ? println(1) : 
    x + 1 == 3 ? println(2) :
    x == 3     ? println(3) :
    println("greater than 3")
end

do i = start_value, end_value, step
    ...
end do

for i in start:step:end
    ...
end

do while <logical expr>
    ...
end do

while <logical expr>
    ...
end

exit

break

cycle

continue

integer(kind=8) :: n = 0
real(kind=8) :: x = 0.

n = 0
n :: Int64 = 0
x = 0.
x :: Float64 = 0.

integer, parameter :: answer = 42
real(8), parameter :: pi = 4d0 * atan(1d0)

const answer = 42

complex :: z = (1., -1.)

z = 1 - 1im
z = complex(1, -1)

character(len=10) :: str_fixed_length
character(len=:), allocatable :: str_var_length

string = "this is a string"

real, pointer :: p
real, target :: r
p => r

p = Ref(r)

.true.
.false.

true
false

.not.
.and.
.or.
.eqv.
.neqv.

!
&&
||

==, .eq.

==

/=, .ne.

!==

>, .gt.

>

<, .lt.

<

>=, .ge.

>=

<=, .ge.

<=

real(8), dimension(3) :: a = [1., 2., 3.]

a = [1., 2., 3.]

character(len=20), dimension(3, 4) :: char_arr

char_arr = String[]
push!(char_arr, new_string)

a op b

a(1)

a[1] (or a[begin] for general indexing) 

a(1:5)

a[1:5] (or @view(a[1:5]) for non-allocating slicing)

a(1:100:2)

a[1:2:100]

size(a)

length(a)

shape(a)

size(a)

size(a, dim)

size(a, dim)

int(x)

trunc(Int, x )

nint()

round()

real(a[, kind])

float()

real(z[, kind])

real()

cmplx(x [, y [, kind]])

complex()

logical()

Bool()

type Point
    real(8) :: x, y
end type Point

struct Point
    x :: Float64
    y :: Float64
end

type(Point) :: point1 = Point(-1., 1.)

point1 = Point(-1., 1.)

point1%x
point1%y

point1.x
point1.y

type(Point), dimension(:), allocatable :: point_arr

point_arr = Vector{Point}

type(Circle) :: c
call c%print_area

c = Circle()
print_area(c)

abs(), cos(), cosh(), exp(), floor(), log(),
log10(), max(), min(), sin(), sinh(), sqrt(),
sum(), tan(), tanh(), acos(), asin(), atan()

aimag()
atan2(x, y)
ceiling()
conjg(z)
modulo()
call random_number()

imag()
atan(x, y)
ceil()
conj()
mod(), %
Random.rand()

len()

length()

iachar()

Int()

achar()

String()

index(string, substring)

findfirst(substring, string)

"hello" // "world"

"hello" * "world"
string("hello", "world")

where a > 0
    b = 0
elsewhere
    b = 1
end where

b[a .> 0] .= 0
b[a .<= 0] .= 1

for i in eachindex(a)
    a[i] > 0 ? b[i] = 0 : b[i] = 1
end

    
integer, parameter :: n = 20
integer, parameter :: m = n*(n+1)/2
integer :: i, j
complex, dimension(m) :: a
a = [ ( ( cmplx(i,j), i=j,n), j=1,n) ]

a = [ complex(i,j) for j=1:n for i=j:n]

real, dimension(10, 10) :: a = 0
int :: i, j
...
forall (i = 1:10, j = 1:10, i <= j)
    a(i, j) = i + j
end forall

a = zeros(Float32, 10, 10)
for i in 1:10, j in 1:10
    if i <= j
        a[i, j] = i + j
    end
end

call cpu_time()

time = @elapsed begin
...
end

call command_argument_count()
call get_command()
call get_command_argument()

print fmt, <output list>

println()

read fmt, <input list>

readline()

open(unit, file, ...)

f = open(file, 'r')

read(unit, fmt, ...) <input list>

read(f)
readlines(f)

write(unit, fmt, ...) <output list>

write(f, ...)

close(unit, ...)

close(f)

inquire(unit, ...)

isfile("my_file.txt")

backspace(unit, ...)

skip(f, -1)

endfile(unit, ...)

seekend(f)

rewind(unit, ...)

seekstart(f)