View Compilation Error

0_0_39122327_9912.cpp: In function 'int main()':
0_0_39122327_9912.cpp:8:23: error: 'i' was not declared in this scope
    8 |         scanf("%d",&a[i]);
      |                       ^
0_0_39122327_9912.cpp:12:9: error: 'i' was not declared in this scope
   12 |     for(i=0;i<4;i++)//1
      |         ^