View Compilation Error

0_0_33174675_21767.cpp: In function 'int main()':
0_0_33174675_21767.cpp:11:13: error: expected ']' before ';' token
    char a[50;
             ^
0_0_33174675_21767.cpp:16:8: error: 'a' was not declared in this scope
     if(a[0]=='0'||a[0]>'0'||a[0]<'9'||a[0]==9||a[0]==' ')
        ^
0_0_33174675_21767.cpp:18:8: error: 'a' was not declared in this scope
     if(a[i]=='a'||a[i]>'a'||a[i]=='z'||a[i]<'z'||a[i]=='A'||a[i]>'A'||a[i]=='Z'||a[i]<a[i]<'Z'||a[i]=='-')
        ^