如何初始化所有元素为0的二维数组？

Question

I want to initialise a 2d array having all its elements are 0. I have tried this:

scanf("%d",&n);
int arr[n][n]={0};

but i got the [Error]:"variable-sized object may not be initialized"

So,how to do this?

Answer 1

Be explicit.

#include <string.h>

const int got = scanf("%d", &n);
int arr[n][n];
memset(arr, 0, sizeof arr);

Note that if got isn't 1, the above has undefined behavior. This is pretty dangerous.

Answer 2

Do in two steps:

int a[n][n];
for(int i=0;i<n;i++)
{
   for(int j=0;j<n;j++)
   {
      a[i][j] = 0;
   }
}

Answer 3

probably the simplest method

for(i = 0; i < n; i++)
{
    for(j = 0; j < n; j++)
    {
        a[i][j] = 0;
    }
}

Answer 4

use #include<string.h> library well we have three methods to initialise it to 0

// the best and easy is using memset

int n;
scanf("%d",&n);
int array_d[n][n];

memset(array_d,0,sizeof(array_d));

// syntax memset(address_of_arr,anyvalue_u_want_Tointialise,sizeof_the_array_or_bytes); //hope u get it

case 2 // if it is global array then

int arr[1000][1000]={0};

case 3

//using for loop

for(int =i;i<n;i++)
{

for(int j=0;j<n;j++)
{
arr[i][j]=0;
}

}