#include <iostream>
int main(){
using namespace std;
string s1("Hello1");
string s2("Hello2");
for(int i = 0; i < 3; i ){
cout.width(20); cout<<"Some String:"<<left<<s1<<endl;
cout.width(20); cout<<"Another String:"<<left<<s2<<endl;
cout<<endl;
}
return 0;
}
Here is my code. It, to my knowledge, should print s1 and s2 20 characters from the very left of the screen. However, it prints
Some String:Hello1
Another String: Hello2
Some String: Hello1
Another String: Hello2
Some String: Hello1
Another String: Hello2
I am using onlineGDB to compile, as per instruction of my teacher. What error am I making?
CodePudding user response:
std::left
is a "sticky" manipulator, meaning you just set it once. By default, padded strings will be right-justified, which is what happens when you output "Some String:"
before ever applying the std::left
manipulator.
See the documentation which states:
The initial default for standard streams is equivalent to
right
.
Fixing your code, and tidying it up a bit:
#include <iostream>
#include <iomanip>
int main()
{
using namespace std;
string s1("Hello1");
string s2("Hello2");
cout << left;
for(int i = 0; i < 3; i ) {
cout << setw(20) << "Some String:" << s1 << endl;
cout << setw(20) << "Another String:" << s2 << endl;
cout << endl;
}
return 0;
}
Output:
Some String: Hello1
Another String: Hello2
Some String: Hello1
Another String: Hello2
Some String: Hello1
Another String: Hello2
Note that I used std::setw
I/O manipulator from <iomanip>
instead of the call to cout.width()
. This makes the code easier to read and follow.
See the documentation for std::setw
CodePudding user response:
this statment says
cout.width(20); cout<<"Some String:"<<left<<s1<<endl;
set column width to 20,
output "Some String:"
start left justifying
output s1
output end of line
you mean
cout.width(20);
cout << left;
cout<<"Some String:" << s1 << endl;