Thread: pointer coding

  1. #1
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    pointer coding

    Code:
    #include <stdio.h>
    #include <conio.h>
    void fun(int , int*);
    int main(void){
    int a, i;
    int x = 100,y = 200, z = 300;
    int myArr[] = {18,22,3};
    int *ptr1, *ptr2;
    ptr1 = &y;
    ptr2 = &z;
    printf("%d\n",*ptr1 + x);
    a = *ptr2;
    ptr2 = &x;
    printf("%d %d\n",a, *ptr2);
    fun(a, myArr);
    ptr1 = myArr;
    printf("%d\n",*ptr1++);
    ptr1--;
    printf("%d\n",--(*ptr1));
    getch();
    return 0;
    }
    void fun(int b , int* pr){
    int *p;
    for(p = pr; p < pr+3; p++)
    *p = *p + b;
    printf("%d\n",*--p);
    }
    For the coding above, what will *p be? what is the value? I have problems tracing this coding..

  2. #2
    C++ Witch laserlight's Avatar
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    Compile and test. You can also use a debugger.
    Quote 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

  3. #3
    and the hat of int overfl Salem's Avatar
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    > I have problems tracing this coding..
    Perhaps some indentation, and the occasional blank line to space things out would help.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

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