How to fix errors in my Fortran code - fortran

Question

I am not familiar with errors in Fortran. Could you please explain what are these errors?
int.f90(18): error #5082: Syntax error, found IDENTIFIER 'K' when expecting one of: ( % : . = =>
do k=0.0 to m
---^
int.f90(19): error #5082: Syntax error, found IDENTIFIER 'Q' when expecting one of: ( % : . = =>
do q=1 to m-1
----^
int.f90(20): error #5082: Syntax error, found END-OF-STATEMENT when expecting one of: ) ,
f1=1/(2*pi)*(sqrt((k**2)+(Q**2)-(2*k*cos(t)))
----------------------------------------------^
int.f90(24): error #5082: Syntax error, found IDENTIFIER 'I' when expecting one of: ( % : . = =>
do i=1 to m-1
----^
int.f90(4): error #6406: Conflicting attributes or multiple declaration of name. [INT]
function int(f,a,b,int,m)
-------------------^
int.f90(9): error #6418: This name has already been assigned a data type. [M]
integer:: i,m
------------^
int.f90(10): error #6557: An =initialization-expr is missing; an initialization expression is required when using the PARAMETER attribute. [PI]
real,parameter:: pi,pi=3.14
-----------------^
int.f90(10): error #6418: This name has already been assigned a data type. [PI]
real,parameter:: pi,pi=3.14
--------------------^
int.f90(11): error #6557: An =initialization-expr is missing; an initialization expression is required when using the PARAMETER attribute. [EPS]
real,parameter:: eps,eps=1.89
-----------------^
int.f90(11): error #6418: This name has already been assigned a data type. [EPS]
real,parameter:: eps,eps=1.89
---------------------^
int.f90(12): error #6557: An =initialization-expr is missing; an initialization expression is required when using the PARAMETER attribute. [E]
real,parameter:: e,e=1.602*((10)**(-19))
-----------------^
int.f90(12): error #6418: This name has already been assigned a data type. [E]
real,parameter:: e,e=1.602*((10)**(-19))
-------------------^
int.f90(21): error #6099: An ENDDO statement occurred without a corresponding DO or DO WHILE statement.
end do
-^
int.f90(23): error #6099: An ENDDO statement occurred without a corresponding DO or DO WHILE statement.
end do
-^
int.f90(26): error #6410: This name has not been declared as an array or a function. [F2]
s=2*f2(t)+4*f2(t+h)
-----^
int.f90(27): error #6099: An ENDDO statement occurred without a corresponding DO or DO WHILE statement.
end do
-^
and this is my code:
function int(f,a,b,int,m)
implicite none
double precision f1,f2,a,b,m,int,s
double precision h,t
integer:: k,q
integer:: i,m
real,parameter:: pi,pi=3.14
real,parameter:: eps,eps=1.89
real,parameter:: e,e=1.602*((10)**(-19))
a=0.0
b=pi
m=150
s=0.0
h=(b-a)/m
do k=0.0 to m
do q=1 to m-1
f1=1/(2*pi)*(sqrt((k**2)+(Q**2)-(2*k*cos(t)))
end do
f2=((2*pi*(e**2))/eps)*f
end do
do i=1 to m-1
t=a+(i*h)
s=2*f2(t)+4*f2(t+h)
end do
int=(h/3)*(s+f2(a)+f2(b)+4*f2(a+h))
print*,int
return
end function int

Answer 1

Your errors are:
Your loop-control in every one of your do loops is malformed. (Fortran 2008 Cl. 8.1.6.2 R818)
DO loops are specified as (neglecting optional syntax):
do variable=start, end
Note the comma rather than the word to.
Parenthesis must be balanced. (See Fortran 2008 7.1.2.2 R701 ( expr ))
Every left parenthesis ( must have a corresponding right parenthesis ). Your statements assigning f1 and f2 both have more left parenthesis than right parenthesis.
Declaring a variable twice in the same scoping unit is wrong. (Fortran 2008 Cl. 16.3.1 paragraph 3, see also: Cl. 5.2)
To delcare a variable and initialize it, you need only use its name once
real, parameter :: pi=3.14
You call the function int and a dummy variable int. You need to use different names for these.
You declare m as both integer and double precision. You can only declare it as one type, not two.
Of note:
Fix errors starting with the first ones, as later ones can be caused by the compiler throwing out earlier bad statements and will go away when those are fixed.
Real values in do loop variables are deleted in the latest standard, and should be avoided in new code. (Fortran 2008 Annex B.1 2(1)).
Your code demonstrates a lack of understanding in Fortran and you will benefit greatly from finding a Fortran tutorial that covers the basics of variables and loops.