help me out

[EwCiz8AR]

why this program not working with string data type when i use char data type instead of string so this program run easily but not with string???

  #include<iostream.h>
#include<string>
using namespace std;
main(){
string a;
cin>>a;
cout<<stlwr(string a);}

[Awareness]

Maybe you should use

cout<<strlwr(a);

?

[EwCiz8AR]

yep i try this but not working:(

[Awareness]

strlwr requires you to use char* not string I think.

[nvrmnd]

The Reason it doesn't work is because strlwr is originally a C function (and a non standard), and C doesn't know/have a std::string type; (class) therefore it doesn't have a implementation for it

There are also some issues w/ your code :
<iostream.h> must be <iostream> main must be int main()
remove string in line 7, we don't need to include the type when passing arguments

Consider using this function instead ( for std::string )

std::string strlwr ( std::string& str )
{
    std::string temp( str );
    for( auto& i : temp )
        i = tolower( i );
    
    return temp;
}

note compile it w/ -std=c++11

EX :

#include <iostream>
#include <string>

std::string strlwr ( std::string& str )
{
    std::string temp( str );
    for( auto& i : temp )
        i = tolower( i );
    
    return temp;
}

int main()
{
    std::string str( "HELLO" );
    std::cout << strlwr( str );
}

remove the std:: prefixes if you have using namespace std;