Error called object is not a function or function pointer

I am trying to write a program which implements the Pop and Push functions. The problem is, I am trying to pass the pointer that points to integer Top to the function, so that this integer keeps changing, but when I try to compile I always get this line:

**error: called object is not a function or function pointer (*t)—

#include<stdio.h>
#include<stdlib.h>

#define MAX 10
int push(int stac[], int *v, int *t)
{
  if((*t) == MAX-1)
  {
      return(0);
  }
  else
  {
      (*t)++;
      stac[*t] = *v;
      return *v;
   }
}

int pop(int stac[], int *t)
{
 int popped;
 if((*t) == -1)
 {
      return(0);
 }
 else
 {
     popped = stac[*t]
     (*t)--;
     return popped;
 } 
}
int main()
{
int stack[MAX];
int value;
int choice;
int decision;
int top;
top = -1;
do{
   printf("Enter 1 to push the valuen");
   printf("Enter 2 to pop the valuen");
   printf("Enter 3 to exitn");
   scanf("%d", &choice);
   if(choice == 1)
   {
       printf("Enter the value to be pushedn");
       scanf("%d", &value);
       decision = push(stack, &value, &top);
       if(decision == 0)
       { 
           printf("Sorry, but the stack is fulln");  
       }
       else
       {
           printf("The value which is pushed is: %dn", decision);
       }
   }
   else if(choice == 2)
    {
         decision = pop(stack, &top);
        if(decision == 0)
          {
               printf("The stack is emptyn");
          }
         else
          {
              printf("The value which is popped is: %dn", decision);
          }

    }
 }while(choice != 3);
 printf("Top is %dn", top);

}

1. 03-18-2012

   
   

   #1

   

   
   Registered User
   

   ---

   Called Object type is not a function or function pointer (probably beginner mistake)
   

   Hey guys, I’ve just started coding C about a week ago and I’m getting an error in two lines of code one saying «Called object type ‘int’ is not a function or function browser» and «Called object type ‘int’ is not a function or function browser». I’d like to know why that’s happening in my program but also what that means in general. Another one that isn’t actually failing the build is «Conversion specifies build type ‘double’ but the argument has type ‘double *’, and I was wondering what that means. All the errors are in the «a series» function. The point of the code in this section is to loop a certain number of times, (entered by the user(n)) adding a function during each iteration of the loop, with a time input (t). Thanks for the help. Here’s the code

   Code:

   #include <stdio.h>
   #include <time.h>
   #include <math.h>
   #define pi 3.141593
   
   
   int aseries();
   int bseries();
   int cseries();
   
   
   int main()
   {
   //Beginning program stuff
   
       
   //Defining variables to find the time
       time_t now;
       time(&now);
       printf("%sn", ctime(&now));
   printf("--------------------------------------------------------------n");
       
   //Main Program
       char choice;
   printf("What type of evaluation would you like to perform?nt1.)Calculate voltage for a given value of time.nt2.)Input t and epsilon.nt3.)Find the change in voltage between t2 and t1.nEnter '1' for choice one, '2' for choice two, or '3' for choice three: ");
       scanf("%d",&choice);
       
       if (choice == 1){
           aseries();
       }
   
   
       if (choice == 2){
           bseries();
       }
       
       if (choice == 3){
           cseries();
       }
       
       
       
       return 0;
   }
   
   
   int aseries()
   {
       
       double t;
       int n;
       double total=0;
       double v;
   
   
       
       
   //Prompting the user for time input
   printf("Enter the time you would like to evaluate the voltage at: ");
       scanf("%lf",&t);
       
   //Prompting the user for number of terms in the series
   printf("Enter the number of terms in the series you would like: ");
       scanf("%lf",&n);
       
   //Building the series
       
       for (int i=0;i<=n;i++){
         total = total + ((1/((2(i)-1)^2))*cos(((2(i)-1)*pi*t)/3)) //This is where the "Called object type 'int'..." error is 
           
       }
       
       v=(3/2)-(12/pow(pi,2))(total); //This is where the "Called object type 'double'..." error is 
       
       printf("%lf",&v); //This is where the "Conversion specifics type..." error is 
       
       
       
       
       
       return 0 ;   
   
   
   }
   
   
   int bseries()
   {
       double t;
       double e;
       
   //Prompting the user for time input
   printf("Enter the time you would like to evaluate the voltage at: ");
       scanf("%lf",&t);
       
   //Prompting the user for epsilon input
   printf("Enter the epsilon value you would like to use: ");
       scanf("%lf",&e);
       
       
       
       return 0;
       
   
   
       
   }
   
   
   int cseries()
   {
       double t1;
       double t2;
       int n;
       
       
   //Prompt the user for time inputs
   printf("Enter the beginning of the time you would like to evaluate the voltage at: ");
       scanf("%lf",&t1);
   
   
   printf("Enter the end of the time you would like to evaluate the voltage at: ");
       scanf("%lf",&t2);
   
   
   //Prompting the user for number of terms in the series
   printf("Enter the number of terms in the series you would like: ");
       scanf("%lf",&n);
       
       return 0;
       
   }

   Last edited by Ethan_K; 03-18-2012 at 09:43 PM.

   ---

2. 03-18-2012

   
   

   #2

   

   
   ATH0
   

   

   ---

   Next time, try including line numbers for those errors. Why did you feel the need to go in and manually color everything?

   Code:

       int n;
   ...    
   printf("Enter the number of terms in the series you would like: ");
       scanf("%lf",&n);

   Quzah.

   Hope is the first step on the road to disappointment.

   ---

3. 03-18-2012

   
   

   #3

   

   
   Registered User
   

   ---

   Originally Posted by quzah
   

   Next time, try including line numbers for those errors. Why did you feel the need to go in and manually color everything?

   Code:

       int n;
   ...    
   printf("Enter the number of terms in the series you would like: ");
       scanf("%lf",&n);

   Quzah.

   The code was already colored from Xcode. And I changed the %lf to a %d, but it didn’t fix any of the errors.

   ---

4. 03-18-2012

   
   

   #4

   

   
   ATH0
   

   

   ---

   Code:

    total = total + ((1/((2(i)-1)^2))

   All of that is integer math. ^ is not power of, it’s XOR. I don’t know what you think 2(i) does, but it doesn’t do what you think it does.

   Quzah.

   Hope is the first step on the road to disappointment.

   ---

5. 03-18-2012

   
   

   #5

   

   
   spurious conceit
   

   

   ---

   Originally Posted by Ethan_K
   

   The code was already colored from Xcode.

   If you set whatever in Xcode so that it exports plain text instead, the forum will highlight and add line numbers. Then you can include the line number of the errors. That is a little simpler and more obvious than adding comments to the same effect.

   Lose the address of operator & here:

   The «called object…» errors are because you need to add some multiplication signs, *. You can’t use «2(3+1)», you have to use «2*(3+1)».

   Beware what quzah said about ^ not being the operator you may think it is.

   ---

6. 03-18-2012

   
   

   #6

   

   
   Registered User
   

   ---

   Alright yeah thanks, I’m still adjusting to syntax differences between this and matlab. I switched out the ^ for the pow function. And after I removed the & everything appears to be working correctly, so thanks guys! And just to clear things up, the & just points to a variable, right? So for most things I don’t need a pointer, besides scanf()?

   ---

7. 03-18-2012

   
   

   #7

   

   
   — — — — — — — —
   

   

   ---

   Here is a better definition of PI (and note that manifest constants are conventionally spelled in uppercase). Put this after your includes at the top of the program. (The ifndef is just in case math.h has already defined it.)

   Code:

   #ifndef M_PI
   #define M_PI 3.1415926535897932385
   #endif
   
   #define PI_SQUARED (M_PI * M_PI)

   Note that because of the way integer division works in C, the expression (3 / 2) will give exactly 1. Better to simply use 1.5. Also, it’s often best to avoid the pow function for simply squaring a number. So taking all that on board, try something like:

   Code:

   double a;  /* Give this a better name if you can think of one. */
    . . .
   a = 2 * i - 1;
   total += 1 / (a * a) * cos(a * M_PI * t / 3) 
   v = 1.5 - 12 / PI_SQUARED * total;

   The cost of software maintenance increases with the square of the programmer’s creativity. — Robert D. Bliss

   ---

8. 03-18-2012

   
   

   #8

   

   
   spurious conceit
   

   

   ---

   Originally Posted by Ethan_K
   

   Alright yeah thanks, I’m still adjusting to syntax differences between this and matlab. I switched out the ^ for the pow function. And after I removed the & everything appears to be working correctly, so thanks guys! And just to clear things up, the & just points to a variable, right? So for most things I don’t need a pointer, besides scanf()?

   & returns the address of a variable (aka, a pointer to it). With the scanf() input functions, you want to pass in an address so scanf can write to it. With the printf() output functions, you are providing a value to read. So if you have an int x, x refers to that value; &x also refers to a value, but it is the value of the address where x is stored, which is usually not meaningful for output.

   Screw around and have a look at the difference. If you are printing addresses on purpose, use %p (the p is for pointer).

   ---

9. 03-19-2012

   
   

   #9

   

   
   Registered User
   

   ---

   Alright, this thread has cleared up a ton of confusions, thanks everyone!

   Edit:

   Originally Posted by oogabooga
   

   
   Note that because of the way integer division works in C, the expression (3 / 2) will give exactly 1. Better to simply use 1.5. Also, it’s often best to avoid the pow function for simply squaring a number.

   To tell C to do double/float division it seems like putting a decimal after the numbers works (e.g. 3.0/2.0) is that correct? And for the pow function, it’s better just to use multiplication because it takes less resources?
   

   Last edited by Ethan_K; 03-19-2012 at 08:48 AM.

   ---

10. 03-19-2012

    
    

    #10

    

    
    — — — — — — — —
    

    

    ---

    Originally Posted by Ethan_K
    

    To tell C to do double/float division it seems like putting a decimal after the numbers works (e.g. 3.0/2.0) is that correct? And for the pow function, it’s better just to use multiplication because it takes less resources?

    Yep. Sounds like you’re getting the hang of it.

    The cost of software maintenance increases with the square of the programmer’s creativity. — Robert D. Bliss

    ---

11. 03-19-2012

    
    

    #11

    

    
    Registered User
    

    ---

    Alright guys, everything is seemingly working correctly, as far as the compiler is concerned. However, something is going wrong when building the series: the math is going wrong after the first loop (The printf’s are in there just to see what’s going on in the loop). I made the series building equation it’s own function to save on retyping it.

    Code:

    double buildseries(double t, int n){    
    
    
        double a=0,v=0,total=0;
    
    
        
        
        for (int i=1;i<=n;i++){
            printf("i = %dn",i);
            a = 2.0 * i - 1.0;
            printf("a = %lfn",a);
            total += 1.0 / (a * a) * cos(a * M_PI * t / 3.0);
            printf("total = %lfn",total);
        }
        
        v = (3.0/2.0) - 12 / PI_SQUARED * total;
    
    
        
        return v;

    I tested the output with t = 2.4 and n = 3 and this is the output:

    i = 1
    a = 1.000000
    total = -0.809017
    i = 2
    a = 3.000000
    total = -0.774682
    i = 3
    a = 5.000000
    total = -0.734682
    t = 2.4
    n = 3
    V = 2.393266

    The a values are correct, but the total values are wrong after the first one and I’m not sure what’s causing it. According to my calculator (which is in radians) the second ‘total’ value should be .0343352216, and the third ‘total’ value should be .04.

    Thanks again guys.

    ---

12. 03-19-2012

    
    

    #12

    

    
    C++ Witch
    

    

    ---

    What is the formula that you are trying to implement? Maybe the bug is with that implementation.

    Originally Posted by Bjarne Stroustrup (2000-10-14)

    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. «Finding the smallest program that demonstrates the error» is a powerful debugging tool.

    Look up a C++ Reference and learn How To Ask Questions The Smart Way

    ---

13. 03-19-2012

    
    

    #13

    

    
    Registered User
    

    ---

    Originally Posted by laserlight
    

    What is the formula that you are trying to implement? Maybe the bug is with that implementation.

    

    ---

14. 03-20-2012

    
    

    #14

    

    
    Registered User
    

    ---

    Whoops I was making a very foolish mistake and calculating the total each time while checking the math, not actual the sum of the totals each time- so everything is working fine. Time to stop late night coding…

    ---

That’s not how I’d do it.

…

then invoke with a function-like macro call. e.g:

SET_TCB0_MODE(TCB0_MODE_FREQ_MEASUREMENT);
Note that both the bit constants to be assigned and the mask for them are shifted ‘up’ the register by pozn so that enum can be used to declare them even for groups of bits that don’t include the LSB of the register.  If you need to skip a bit value in the enum, e.g. 0b101, declare it as …_RESERVED101

This is good, and only a modest variation on the way Atmel did it (at least for the MEGA family) already.  A random example from an xmega header:

/* Quadrature Decoder Index Recognition Mode */
typedef enum EVSYS_QDIRM_enum
{
    EVSYS_QDIRM_00_gc = (0x00<<5),  /* QDPH0 = 0, QDPH90 = 0 */
    EVSYS_QDIRM_01_gc = (0x01<<5),  /* QDPH0 = 0, QDPH90 = 1 */
    EVSYS_QDIRM_10_gc = (0x02<<5),  /* QDPH0 = 1, QDPH90 = 0 */
    EVSYS_QDIRM_11_gc = (0x03<<5),  /* QDPH0 = 1, QDPH90 = 1 */
} EVSYS_QDIRM_t;

«_gc» stands for «group configuration», so it is the pattern of bits to set for the desired configuration.  The register is masked with the «_gm» (group mask), and the individual bits with «_bm» (bit mask).

Therefore, a basic modify statement has the form:

port.register = (port.register & ~port_bitgroup_gm) | port_bitgroup_state_gc;
The «& ~» reads the existing register value and zeroes the desired bits; the | puts back in the desired bits.  (The bitmasking can be omitted in the initialization routine, where you don’t need to worry about the initial state of other bits in the register.)

The only reason you should need/want to get fancier, is to be able to change all «port.register» and bitgroup/state references, to a more general definition, in your own headers.

This is more or less what Ian is doing: putting the whole assignment into a macro function.

By encapsulating the assignment in a more general macro, you only have to change, say, a few dozens of register, bit and group names.

You definitely don’t want to maintain exhaustive lists of bits, that will accumulate errors faster than you can say «refactor»!

At the very least, if you insist on building such lists, write a tool to generate them!  That’s how the pros make their headers (well, at least I would hope so..).  That’s also what their headers are for.  Use them!

With this additional level of naming indirection, you can — if nothing else — use them in the same way as the XMEGA style headers, even for platforms that don’t use that format (e.g., original MEGA).  You can get consistent naming conventions across families, or sub-families anyway.  It’s probably a fair method even to support completely different platforms, too (ARM?)!  Though, that’s probably optimistic, and  you may need more (or fewer) statements, on platforms quite that different (i.e., wider-bit devices probably use fewer registers to hold all their control/status bits).

Generality is the key here.  You don’t want to go more specific, less general.  You must only go more general.  To go more specific, means more code refactoring.  More work, more frustration!

It also means this: if you don’t know, in what directions you should generalize — if you aren’t very familiar with the ecosystems of microcontrollers in general — you probably shouldn’t do it at all, and just leave it at the family level.

Make it obvious to the reader, which functions/defines need to be checked/changed, to migrate to a different device/family, and leave it at that.

Better still, if it’s an open project: let other, more experienced programmers fork and improve it.  If you don’t have that kind of breadth of knowledge, don’t make it up as you go — take advantage of those more experienced!

Tim

See more:

error: called object is not a function or function pointer
   47 |       if(orders->product_items(j).sku == products[t].sku)
      |          ^~~~~~
hw4.c:49:22: error: called object is not a function or function pointer
   49 |        TotalCost += (orders->product_items(j).quantity * products[t].price);
      |                      ^~~~~~

struct product {
	short sku;
	char *name;
	float price;
};

struct item {
	short sku;
	short quantity;
};

struct order 
{
	short order_id;
	char *customer_name;
	short num_products;
	struct item *product_items;
};

struct order * read_orders(const char *filename, short *num_orders);

#include <inttypes.h>

#include "orders.h"

struct order * read_orders(const char *filename, short *num_orders)
{
    int fd;
    fd = open(filename, O_RDONLY);
    int err = fd;
    if (err == -1) {
        return NULL;
    }

    read(fd, num_orders, sizeof(*num_orders));
    struct order *orders = (struct order *)
        calloc(*num_orders, sizeof(struct order));

    int i;
    for (i=0; i<*num_orders; i++) {
        struct order *op = &orders[i];
        read(fd, &op->order_id, sizeof(op->order_id));

        uint32_t sz;
        read(fd, &sz, sizeof(sz));
        op->customer_name = (char *)malloc(sz+1);
        read(fd, op->customer_name, sz);
        op->customer_name[sz] = 0;

        read(fd, &op->num_products, sizeof(op->num_products));
        op->product_items = (struct item *)
            calloc(op->num_products, sizeof(struct item));

        int j;
        for (j=0; j<op->num_products; j++) {
            struct item *ip = &(op->product_items[j]);
            read(fd, &ip->sku, sizeof(ip->sku));
            read(fd, &ip->quantity, sizeof(ip->quantity));
        }
    }

    close(fd);
    return orders;
}

<pre>#include <stdio.h>
#include <stdlib.h>
#include "orders.h"

struct product products[] = {
		{
		1234, "Bread", 2.99
	},
	{
		5678, "Milk", 4.19
	},
	{
		9012, "Eggs", 3.49
	},
	{
		3456, "Butter", 3.99
	},
	{
		7890, "Juice", 2.49
	},
	{
		2345, "Muffin", 1.49
	}
};

int main()
	{
		short num_orders;
		struct order *orders = read_orders("orders.db", &num_orders);
		if (orders == NULL)
		{
			printf("Order database does not existn");
		}

		
		for (int i = 0; i < num_orders; i++)
		{
			
			float TotalCost = 0;
			
			printf("Order ID: %hd", orders[i].order_id);
			printf("Name: %sn", orders[i].customer_name);
			for (int j = 0; j < orders[i].num_products; j++) 
			{
				for (int t = 0; t< 6; t++)
				{
						if(orders->product_items(j).sku == products[t].sku)
						{
							TotalCost += (orders->product_items(j).quantity * products[t].price);

							printf("%s %hd %f/n", products[t].name, orders->product_items[j].quantity, products[t].price);
						}
				}
				
			}
			printf("Total: %fn",TotalCost);
			printf("n");
			}
		}