View Compilation Error

0_0_28655638_1046.cpp: In function 'void clear()':
0_0_28655638_1046.cpp:5:9: error: invalid use of non-static data member 'BigNum::L'
     int L,x[1003];
         ^
0_0_28655638_1046.cpp:6:25: error: from this location
     friend void clear(){L=0;memset(x,0,sizeof(x));}
                         ^
0_0_28655638_1046.cpp:5:17: error: invalid use of non-static data member 'BigNum::x'
     int L,x[1003];
                 ^
0_0_28655638_1046.cpp:6:36: error: from this location
     friend void clear(){L=0;memset(x,0,sizeof(x));}
                                    ^
0_0_28655638_1046.cpp: In function 'BigNum operator+(BigNum, BigNum)':
0_0_28655638_1046.cpp:9:20: error: 'struct BigNum' has no member named 'clear'
         BigNum c;c.clear();int L=max(a.L,b.L);
                    ^
0_0_28655638_1046.cpp: In function 'void Input(BigNum&)':
0_0_28655638_1046.cpp:17:11: error: 'struct BigNum' has no member named 'clear'
         a.clear();char s[1000];scanf("%s",s);a.L=strlen(s);
           ^