解释C编程中的编译时初始化和运行时初始化

type name[size] = { list_of_values };
//integer array initialization
int rollnumbers[4]={ 2, 5, 6, 7};
//float array initialization
float area[5]={ 23.4, 6.8, 5.5,7.3,2.4 };
//character array initialization
char name[9]={ 'T', 'u', 't', 'o', 'r', 'i', 'a', 'l', '\0' };

#include<stdio.h>
void main(){
   //Declaring array with compile time initialization//
   int array[5]={1,2,3,4,5};
   //Declaring variables//
   int i;
   //Printing O/p using for loop//
   printf("Displaying array of elements :");
   for(i=0;i<5;i++){
      printf("%d ",array[i]);
   }
}

Displaying array of elements :1 2 3 4 5

#include<stdio.h>
void main(){
   //Declaring the array - run time//
   int A[2][3],B[2][3],i,j,sum[i][j],product[i][j];
   //Reading elements into the array's A and B using for loop//
   printf("Enter elements into the array A: </p><p>");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         printf("A[%d][%d] :",i,j);
         scanf("%d",&A[i][j]);
      }
      printf("</p><p>");
   }
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         printf("B[%d][%d] :",i,j);
         scanf("%d",&B[i][j]);
      }
      printf("</p><p>");
   }
   //Calculating sum and printing output//
   printf("Sum array is : </p><p>");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         sum[i][j]=A[i][j]+B[i][j];
         printf("%d\t",sum[i][j]);
      }
      printf("</p><p>");
   }
   //Calculating product and printing output//
   printf("Product array is : </p><p>");
   for(i=0;i<2;i++){
      for(j=0;j<3;j++){
         product[i][j]=A[i][j]*B[i][j];
         printf("%d\t",product[i][j]);
      }
      printf("</p><p>");
   }
}

Enter elements into the array A:
A[0][0] :A[0][1] :A[0][2] :
A[1][0] :A[1][1] :A[1][2] :
B[0][0] :B[0][1] :B[0][2] :
B[1][0] :B[1][1] :B[1][2] :
Sum array is :
000
000
Product array is :
000
000