Basic Calculator(Why test cases are failed) pls rectify

#1

#include
using namespace std;
int main() {
int i=1;
while(i!=0){
long long int n1,n2;
int c;
char ch;
cin>>ch;
if(ch==’+’){
cin>>n1>>n2;
c=n1+n2;
cout<<c<<endl;
}
else if(ch==’-’){
cin>>n1>>n2;
c=n1-n2;
cout<<c<<endl;
}
else if(ch==’’){
cin>>n1>>n2;
c=n1n2;
cout<<c<<endl;
}
else if(ch==’/’){
cin>>n1>>n2;
c=n1/n2;
cout<<c<<endl;
}
else if(ch==’%’){
cin>>n1>>n2;
c=n1%n2;
cout<<c<<endl;
}
else if(ch==‘X’||ch==‘x’){
break;
}
else{
cout<<“Invalid operation.Try again”<<endl;
}
i++;
}
return 0;
}

#2

@Ramitcodingblocks
The statement is
“Invalid operation. Try again.”
and NOT
“Invalid Operation .Try again.”

Check after correcting this.