How to assign values in an array of arrays properly?-CodePudding

Is there a way to assign values in an array of arrays?

Specifically, I have written the following code:

#include <stdio.h>
#include <stdlib.h>

void func(int **A){  //A: address of (address that the pointer stores)
  int i;
  *A=(int *)malloc(5*sizeof(int));    //*A: address that the pointer stores
  for (i=0;i<5;i  ){
    **A=i;          //**A: content
  }
}

int main(){
  int *k, i;
  func(&k);

  for (i=0;i<5;i  ){
    printf("%d ", k[i]); 
  }
  return 0;
}

The statement **A=i inside the function, seems to assign the values only in the first place of the array (the output is 4 0 0 0 0 each time I execute the code).

I have also tried using *A[i]=i instead. In this case, the compiler terminates the execution with the following message: signal: illegal instruction (core dumped) .

Is there anything I could do to solve this?

CodePudding user response：

There are several equivalent constructions that allow to do that.

Here you are

for (i=0;i<5;i  ){
  A[0][i] = i; 
}

for (i=0;i<5;i  ){
  ( *A )[i] = i;
}

for (i=0;i<5;i  ){
  *( *A   i ) = i;
}

CodePudding user response：

The array index operator [] has higher precedence than the dereference operator *.

You'll need to use parenthesis do what you want.

(*A)[i]=i;