can array be assigned a pointer ?

This is a discussion on can array be assigned a pointer ? within the C++ Programming forums, part of the General Programming Boards category; Code: main(){ CountingSort c ; int inputArray[10] = {23,12,45,46,25,12,32,43,32,29}; int* outputA; c.setInputArray(inputArray); inputArray = c.sort(); /* for (int i=0;i<10;i++) cout<<setw(3)<<inputArray[i]<<endl;*/ ...

  1. #1
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    Unhappy can array be assigned a pointer ?

    Code:
    main(){
          CountingSort c ;
          int inputArray[10] = {23,12,45,46,25,12,32,43,32,29}; 
          int* outputA;
          c.setInputArray(inputArray);
          inputArray = c.sort();
         
         /* for (int i=0;i<10;i++)
              cout<<setw(3)<<inputArray[i]<<endl;*/      
          getchar();
    }
    c.sort() is a function which is some thing like this
    Code:
    int* CountingSort :: sort(void){
         for(int i=0;i<10 ; i++)
             auxilaryArray[inputArray[i]] = auxilaryArray[inputArray[i]] + 1; 
         for (int i=1;i<SIZE ; i++)
             auxilaryArray[i] = auxilaryArray[i] +  auxilaryArray[i-1];
          for (int j=0;j<10;j++)
              outputArray[auxilaryArray[inputArray[j]]] = inputArray[j];
              
          for (int i=0;i<10;i++)
              cout<<setw(3)<<outputArray[i]<<endl; 
         return outputArray;
    }
    it gives me a type incompatible error in types int* to int[10]
    I lost touch in c++ can some one please let me know why. THought that the address can be assigned to array ?.

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    You may have thought that, but it isn't true. An array is a block of contiguous memory, and for sure you can't move it around. You need to copy values into an array one slot at a time.

  3. #3
    spurious conceit MK27's Avatar
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    Code:
    setInputArray(int array[]);  // prototype
    setInputArray(inputArray);  // call
    That's an array pointer, the array is NOT passed by value, so if you modify it inside setInputArray or it's object, it is modified in the source. If you don't plan on doing that, use "const int array[]" and the compiler will warn you if you break your own rule accidently.

    eg:
    Code:
    #include <iostream>
    
    using namespace std;
    
    void test (int ray[]) {
    	int i;
    	for (i = 0; i < 3; i++) cout << ray[i] << endl;
    	ray[1] = 666;
    }
    
    int main(void) {
    	int ray[3] = {1, 2, 3};
    
    	test(ray);
    	cout << ray[1] << endl;
    
    	return 0;
    }
    Last edited by MK27; 06-18-2011 at 09:36 AM.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  4. #4
    Algorithm Dissector iMalc's Avatar
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    You cannot assign anything to an array itself.
    You can only assign stuff to the individual elements.
    My homepage
    Advice: Take only as directed - If symptoms persist, please see your debugger

    Linus Torvalds: "But it clearly is the only right way. The fact that everybody else does it some other way only means that they are wrong"

  5. #5
    C++まいる!Cをこわせ! Elysia's Avatar
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    I just thought I'd mention it, but main must return int.
    main with no return type at all is not valid C++ code.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  6. #6
    ATH0 quzah's Avatar
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    Quote Originally Posted by iMalc View Post
    You cannot assign anything to an array itself.
    Couldn't you overload the assignment operator.


    Quzah.
    Hope is the first step on the road to disappointment.

  7. #7
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    Assignment operators can only be overloaded as member functions of a class type. Since an array is not a class type, it is not possible to overload an assignment operator for it.
    Right 98% of the time, and don't care about the other 3%.

  8. #8
    ATH0 quzah's Avatar
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    Quote Originally Posted by grumpy View Post
    Assignment operators can only be overloaded as member functions of a class type. Since an array is not a class type, it is not possible to overload an assignment operator for it.
    Thanks, now you know why I stay on the C board.

    I was never a fan of C++ and its crazy rules, templates, overloading, etc. Plus declaring variables wherever you wanted bugs the crap out of me (but then they added it to C...).


    Quzah.
    Hope is the first step on the road to disappointment.

  9. #9
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    A lot of those crazy rules in C++ come due to maintaining backward compatibility to C. What goes around comes around, I guess.
    Right 98% of the time, and don't care about the other 3%.

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