View Compilation Error

0_0_33676657_4755.cpp: In function 'void xiao(char*)':
0_0_33676657_4755.cpp:14:19: error: 'len' was not declared in this scope
         for(int i=len-1;i>=0;i--){
                   ^
0_0_33676657_4755.cpp:19:14: error: 'len' was not declared in this scope
         if(s[len-1] == '.') s[len-1] = '\0';
              ^