program arrays
  IMPLICIT NONE
  !Constant to be used in the declaration of the array
  INTEGER, PARAMETER :: SIZE = 3;
  INTEGER array (SIZE);
  INTEGER i;
  LOGICAL found;
  INTEGER valueToSearch;
  INTEGER sum;
  INTEGER minValue, maxValue;
  !Other way of declaring an array of dimension 1 and size SIZE
  REAL, DIMENSION(SIZE) :: A, B
  !Load and init the values of the array, describing which elements are inside.
   A = (/ 8, 9, 10 /);
   !Load and init the values of the array through a for each sentence
   B = (/ (i, i = 1, SIZE) /)
   print *,A
   print *,B
   !Only if both have the same dimension
   A = B
   print *,A
  !Load and init(manually). Two examples.
  DO i = 1, SIZE
    array(i)=i;
 END DO
 
   DO i = 1, SIZE
    read *, array(i)
 END DO
 
 
 !Show
   DO i = 1, SIZE
    print *,array(i)
  END DO
  
!Search for a value  (first apparition)
   i = 1;
   found = .FALSE.;
   valueToSearch = 3;
  do while (i<=SIZE .AND. .not. found)
      if (array(i)== valueToSearch) then
            print *,"(First) Found value at position: ", i
            found = .TRUE.
      end if
      i = i +1;
  end do
  
!Search for  a value  (ALL apparitions)
   i = 1;
  do while (i<=SIZE)
      if (array(i)== valueToSearch) then
            print *," (All) Found value at position: ", i
      end if
      i = i +1;
  end do


!Search for a value  (last apparition)
   i = SIZE;
   found = .FALSE.;
   valueToSearch = 3;
  do while (i>=1 .AND. .not. found)
      if (array(i)== valueToSearch) then
            print *,"(Last) Found value at position: ", i
            found = .TRUE.
      end if
      i = i -1;
  end do

  
!Adding up values
  sum = 0;
   DO i = 1, SIZE
   sum=sum + array(i);
  END DO
  
  print *,"The sum of values is ", sum
  

!Adding up values with a filter
    sum = 0;
   DO i = 1, SIZE
    if (array(i)>3) then
            print *,"Found value at position: ", i
             sum=sum + array(i);
      end if
  END DO
  

 !Find the max value and use of the intrinsic function MAXVAL
  maxValue = array(1)
  DO i = 2, SIZE
    if (array(i)>maxValue) then
            maxValue = array(i);
      end if
  END DO

 print *,"The max  value is ", maxValue,  MAXVAL(array)
 
!Find the min value  and use of the intrinsic function MINVAL
   minValue = array(1)
  DO i = 2, SIZE
    if (array(i)<minValue) then
            minValue = array(i);
      end if
  END DO

 print *,"The min  value is ", minValue, minval(array)
 
 
  
  read *,
  
end program arrays

program arrays
  IMPLICIT NONE
  !Constant to be used in the declaration of the array
  INTEGER, PARAMETER :: SIZE = 3;
  INTEGER array (SIZE);
  INTEGER i;
  LOGICAL found;
  INTEGER valueToSearch;
  INTEGER sum;
  INTEGER minValue, maxValue;
  !Other way of declaring an array of dimension 1 and size SIZE
  REAL, DIMENSION(SIZE) :: A, B
  !Init the values of the array, describing which elements are inside.
   A = (/ 8, 9, 10 /);
   !Inti the values of the array through a for each sentence
   B = (/ (i, i = 1, SIZE) /)
   print *,A
   print *,B
   !Only if both have the same dimension
   A = B
   print *,A
  !Load (manually)
  DO i = 1, SIZE
    array(i)=i;
 END DO
 
   DO i = 1, SIZE
    read *, array(i)
 END DO
 
 
 !Show
   DO i = 1, SIZE
    print *,array(i)
  END DO
  
!Search for a value  (first apparition)
   i = 1;
   found = .FALSE.;
   valueToSearch = 3;
  do while (i<=SIZE .AND. .not. found)
      if (array(i)== valueToSearch) then
            print *,"(First) Found value at position: ", i
            found = .TRUE.
      end if
      i = i +1;
  end do
  
!Search for  a value  (ALL apparitions)
   i = 1;
  do while (i<=SIZE)
      if (array(i)== valueToSearch) then
            print *," (All) Found value at position: ", i
      end if
      i = i +1;
  end do


!Search for a value  (last apparition)
   i = SIZE;
   found = .FALSE.;
   valueToSearch = 3;
  do while (i>=1 .AND. .not. found)
      if (array(i)== valueToSearch) then
            print *,"(Last) Found value at position: ", i
            found = .TRUE.
      end if
      i = i -1;
  end do

  
!Adding up values
  sum = 0;
   DO i = 1, SIZE
   sum=sum + array(i);
  END DO
  
  print *,"The sum of values is ", sum
  

!Adding up values with a filter
    sum = 0;
   DO i = 1, SIZE
    if (array(i)>3) then
            print *,"Found value at position: ", i
             sum=sum + array(i);
      end if
  END DO
  

 !Find the max value  and use of the intrinsic function MAXVAL
  maxValue = array(1)
  DO i = 2, SIZE
    if (array(i)>maxValue) then
            maxValue = array(i);
      end if
  END DO

 print *,"The max  value is ", maxValue,  MAXVAL(array)
 
!Find the min value  nd use of the intrinsic function MINVAL
   minValue = array(1)
  DO i = 2, SIZE
    if (array(i)<minValue) then
            minValue = array(i);
      end if
  END DO

 print *,"The min  value is ", minValue, minval(array)
 
 
  
  read *,
  
end program arrays

This is an example of declaring and iterating over 1-dimension arrays in FORTRAN.

Basic operations with a 1-dimension array

Fortran