asked on

function overload

Hi,

I am using a book to teach myself C++ and
I am having a problem with one of the questions in the book. I did the first part of the question which required me to create a union and display various amounts in hex format.

But it is the second part of the question that I am having trouble with it requires me to:

Use function overloading so a function called showNum() can be used to display each data type. (Same function name, different types of parameters: this requires three different functions to be written, all with the same name; showNum(int), showNum(long), showNum(float)) but with different data types being passed.)

Can you show me how to modify this program
to those specifications.

////////////////////////////////////////////

#include <iostream.h>      // to use cout
#include <stdio.h>      // to use printf

union mixed
{
      int value_int;
      long value_long;
      float value_float;
      unsigned char value_char[8];
};

main()
{
      mixed value_mixed;

      value_mixed.value_int=(int)13420;
      cout << "The integer " << value_mixed.value_int;
      cout << " is stored in memory as " << sizeof(int);
      cout << " bytes as follows: ";
      for (int i=0; i<sizeof(int); i++)
            printf("[%X]", value_mixed.value_char[i]);
      cout << endl;


      value_mixed.value_long=(long)13420;
      cout << "The long " << value_mixed.value_long;
      cout << " is stored in memory as " << sizeof(long);
      cout << " bytes as follows: ";
      for (int j=0; j<sizeof(long); j++)
            printf("[%X]", value_mixed.value_char[j]);
      cout << endl;

      value_mixed.value_float=(float)13420;
      cout << "The float " << value_mixed.value_float;
      cout << " is stored in memory as " << sizeof(float);
      cout << " bytes as follows: ";
      for (int y=0; y<sizeof(float); y++)
            printf("[%X]", value_mixed.value_char[y]);
      cout << endl;
}

*******************************************

Any help you can give me would be appreciated
J_C_2000

nietod

You need to write three functions that have the same name but different types of parameters, like

showNum(int i)
{
cout << i;
};

showNum(float f)
{
cout << f;
};

showNum(long l)
{
cout << l;
};

nietod

You need to write three functions that have the same name but different types of parameters, like

showNum(int i)
{
cout << i;
};

showNum(float f)
{
cout << f;
};

showNum(long l)
{
cout << l;
};

nietod

You could use the functions like this

main()
{
mixed value_mixed;

value_mixed.value_int=(int)13420;
cout << "The integer ";

showNum(value_mixed.value_int);

cout << " is stored in memory as " << sizeof(int);
cout << " bytes as follows: ";
for (int i=0; i<sizeof(int); i++)
printf("[%X]", value_mixed.value_char[i]);
cout << endl;

value_mixed.value_long=(long)13420;
cout << "The long ";

showNum(value_mixed.value_long);

cout << " is stored in memory as " << sizeof(long);
cout << " bytes as follows: ";
for (int j=0; j<sizeof(long); j++)
printf("[%X]", value_mixed.value_char[j]);
cout << endl;

value_mixed.value_float=(float)13420;
cout << "The float ";

showNum(value_mixed.value_float);
cout << " is stored in memory as " << sizeof(float);
cout << " bytes as follows: ";
for (int y=0; y<sizeof(float); y++)
printf("[%X]", value_mixed.value_char[y]);
cout << endl;
}

s_franklin

Few notes:

* Factored out the dumping of the memory
* Removed the need for printf - cout can generally do what printf can if you look at the spec
* I've assumed that you don't need the union integrated with the second example

#include <iostream.h>

void dump(char *valueType, void *value, int size) {
std::cout << "The " << valueType << " is " << size << " bytes as follows:" << endl;
for(int i=0; i< size; i++) {
std::cout << "[" << (hex) << (void *)((char *)value)[i] << "]";
}
std::cout << endl << endl;
}

void showNum(int value) {
std::cout << "The integer value is: " << value << std::endl;
dump("Integer",&value,sizeof(int));
}

void showNum(float value) {
std::cout << "The float value is: " << value << std::endl;
dump("Float",&value,sizeof(float));
}

void showNum(long value) {
std::cout << "The long value is: " << value << std::endl;
dump("Long",&value,sizeof(long));
}

int main()
{
int myInt = 3;
float myFloat = 3.1415;
long myLong = 3;

showNum(myInt);
showNum(myFloat);
showNum(myLong);

return(0);
}

jimmy_carter_2000

ASKER

Got the same error I was getting before
about ambiguos function call. And I do need the union inclusive in this part two.

Shay050799

this is homework !!!!!!!!!!!!!!!!!!!

ASKER CERTIFIED SOLUTION

nietod

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jimmy_carter_2000

ASKER

Switched to short int and it stopped the ambiguos error and the program now works

thanx Nietod

J_C_2000