assign value of pointer array

**zcrself** · 08-17-2009

Code:

 char *name[4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }
     
     i++;
  }

result: error!

why?

**zacs7** · 08-17-2009

Because name[4] is out of bounds.

You might want to look-up what i++ and k++ actually mean.
More specifically, what the Boolean expression (i++ < 4) means...

Code:

int i = 3;
if(i++ < 4)
   printf("I solved my own question\n");

**strider1974** · 08-17-2009

Not sure what you are trying to do but the code is attempting to insert values at name[4] which is outside the array index

[edit: Beaten to the punch by zacs7]

**zcrself** · 08-17-2009

Originally Posted by zacs7

Because name[4] is out of bounds.

You might want to look-up what i++ and k++ actually mean.
More specifically, what the Boolean expression (i++ < 4) means...

Code:

int i = 3;
if(i++ < 4)
   printf("I solved my own question\n");

Code:

 char *name[4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }
     
     i++;
  }

**zcrself** · 08-17-2009

Originally Posted by strider1974

Not sure what you are trying to do but the code is attempting to insert values at name[4] which is outside the array index

[edit: Beaten to the punch by zacs7]

Code:

 char *name[4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }
     
     i++;
  }

**karimmughal** · 08-17-2009

Code:

char *name[4][4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }

i++;
}

//now u r code is oky.....u r using one dimention pointer array but u using two loop nested it not work....

using two dimention then try.....

**valthyx** · 08-17-2009

Originally Posted by karimmughal

Code:

char *name[4][4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }

i++;
}

//now u r code is oky.....u r using one dimention pointer array but u using two loop nested it not work....

using two dimention then try.....

That is 3 dimension

Code:

char *name[4][4];

**BEN10** · 08-17-2009

Originally Posted by zcrself

Code:

 char *name[4];
 int i = 0;
 while ( i < 4)
 {
     int k = 0;
     while (k < 4)
      {
            *(name[i]+k) = 'c';
            k++;
       }
     
     i++;
  }

result: error!

why?

What are you trying to achieve? name[i] is an address, adding k to it will try to access any random memory which results in segf.

**Elysia** · 08-17-2009

Everyone who posted and modified the original in the beginning needs to take a crash course in C strings.

**bithub** · 08-17-2009

Everyone who posted and modified the original in the beginning needs to take a crash course in C strings.

Everyone? I only see one poster that attempted to modify the original code (karimmughal's post). Everyone else simply pointed out the 2 mains issues with the code.

**Elysia** · 08-17-2009

Everyone who modified it, yes. I see that there is only one aside from the OP, so that's a total of two who needs to take a crash course.

**nonoob** · 08-17-2009

The only problem I see from the original is that there was no storage allocated for name strings. There was never any bounds issue.

**bithub** · 08-17-2009

Originally Posted by nonoob

The only problem I see from the original is that there was no storage allocated for name strings. There was never any bounds issue.

I believe the code in the original post was edited.

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