Thread: Assigning integer to char array.

Hi

I am trying to write a function whihc will convert lower case string to upper case string. I have written the function as below

Code:

char* toUpper(char* str)
{
        int i = 0;
    char *upperStr=str;

       int d=0;
        for(i = 0;i < strlen(str); i++)
        {d = toupper(str[i]);
        upperStr[i]=d;
        }
        upperStr[i] = '\0';
        return upperStr;
}

My code is is failing at the statement upperStr[i]=d.

Can anyone help what could be the reson for this

While i am trying to assign integer value to the first element it is showing code dump

Now it really looks like "trying to modify a string literal". If you call this with

Code:

toUpper("string");

all you're doing is lighting a stick of dynamite and waiting for it to go boom.

Why you should never try to return an array from a function...

Code:

#include <stdio.h>

int* MyFunction(int a, int b, int c)
  {  static int array[3];
     array[0] = a;
     array[1] = b;
     array[2] = c;
     return array;  } // return a pointer.


int main (void)
  { int *a1, *a2;  // int pointers

    printf("calling a1 = MyFunction(10,20,30);\t");
    a1 = MyFunction(10,20,30);
    printf("a1 has %d %d %d\n",a1[0],a1[1],a1[2]);

    printf("calling a2 = MyFunction(100,200,300);\t");
    a2 = MyFunction(100,200,300);
    printf("a2 has %d %d %d\n",a2[0],a2[1],a2[2]);

    printf("\nLooks good, except...\t"); 
    printf("a1 now has %d %d %d\n",a1[0],a1[1],a1[2]);

    getchar();
    return 0; }

Eh, OP is returning the original pointer (like strcpy et al), so that's not actually an issue.

Originally Posted by tabstop

Eh, OP is returning the original pointer (like strcpy et al), so that's not actually an issue.

Ok... My bad.

Originally Posted by CommonTater

Ok... My bad.

Actually, it is a good point though, because I'll bet like anything that the OP thought he was making a brand new copy with fresh pristine memory, and not overwriting the original (e.g., being careful to null-terminate the "new" string). If so, then OP needs to look at malloc.