int A[] = {1,2,3,4};
    int B[sizeof(A)/sizeof(A[0])];
    int index=0;
    for(int i=0;i<theSize;i++)
    {
        if(A[i] < 3)
        {
            B[index]=A[i];
            index++;
        }
    }
    /*show the numbers*/
    for(int i=0;i<index;i++)
    printf("num:%d\n",B[i]);