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Join Date: Feb 2006

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amen

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<string>

Mar 20th, 2006

i input a sentence " i love eat".how can wanto to get c++ to get a full sentence..

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <string>
 
using namespace std;
void echo(string message)
{
cout << message << endl;
}
int main()
{
 
cout << "Enter your word: ";
string word; // place declaration near its use
cin>>word
echo(word);
 
}
#include <iostream>
#include <string>

using namespace std;
void echo(string message)
{
cout << message << endl;
}
int main()
{

cout << "Enter your word: ";
string word; // place declaration near its use
cin>>word
echo(word);

}

but i only get the first word,,how to get the sentence..
i try to use getline(cin,word) but error show up

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Join Date: Aug 2005

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Re: <string>

Mar 20th, 2006

The insertion operator >> stops at the first space. use getline() to get a whole sentence.

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
getline(cin,word);
getline(cin,word);

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Join Date: Feb 2006

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Reputation: amen is an unknown quantity at this point

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amen

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Re: <string>

Mar 20th, 2006

i had do like this

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <string>
 
using namespace std;
void echo(string message)
{
cout << message << endl;
}
int main()
{
 
cout << "Enter your word: ";
string word;
getline(cin,word,'\n');
echo(word);
 
}
#include <iostream>
#include <string>

using namespace std;
void echo(string message)
{
cout << message << endl;
}
int main()
{

cout << "Enter your word: ";
string word;
getline(cin,word,'\n');
echo(word);

}

can i use strtok to token the string

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Join Date: Aug 2005

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iamthwee

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Re: <string>

Mar 20th, 2006

>can i use strtok to token the string

I wouldn't, use some fancy c++ command. Leave 'C' commands where they belong in 'C'.

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Join Date: Sep 2004

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Narue

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Re: <string>

Mar 20th, 2006

>can i use strtok to token the string
Not without first copying the string to an array. The c_str member function gives you a pointer to const char, and strtok modifies the string you pass to it. To do it right, you would end up with something like this:

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 C++ Syntax (Toggle Plain Text) 
char *tstr = new char[line.size() + 1];
char *tok;
 
std::strcpy ( tstr, line.c_str() );
 
tok = std::strtok ( tstr, delim );
 
while ( tok != 0 ) {
  // Process tok
  tok = std::strtok ( tstr, 0 );
}
char *tstr = new char[line.size() + 1];
char *tok;

std::strcpy ( tstr, line.c_str() );

tok = std::strtok ( tstr, delim );

while ( tok != 0 ) {
  // Process tok
  tok = std::strtok ( tstr, 0 );
}

There are better ways than resorting to the C library.

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Join Date: Feb 2006

Posts: 17

Reputation: amen is an unknown quantity at this point

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amen

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Re: <string>

Mar 21st, 2006

but how do i want to compare each token in string with word in text file in c++?

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Re: <string>

Mar 21st, 2006

you can use std::string's find method to locate the spaces

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
int main()
{
std::string line = "Hello World";
std::string word;
int pos;
while( line != "")
{
	pos = line.find(' ');
	if(pos >= 0)
	{
		word = line.substr(0,pos);
		line = line.substr(pos+1);
	}
	else
	{
		word = line;
		line = "";
	}
 
   // now word is just one word
   cout << word << endl;
}
 
}
int main()
{
std::string line = "Hello World";
std::string word;
int pos;
while( line != "")
{
	pos = line.find(' ');
	if(pos >= 0)
	{
		word = line.substr(0,pos);
		line = line.substr(pos+1);
	}
	else
	{
		word = line;
		line = "";
	}

   // now word is just one word
   cout << word << endl;
}

}

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Join Date: Sep 2004

Posts: 7,622

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Narue

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Re: <string>

Mar 22nd, 2006

>but how do i want to compare each token in string with word in text file in c++?
How do you define a token? If it's nothing more than a whitespace delimited sequence of characters, the >> operator may be better suited to your problem because it tokenizes input in such a way by default. Why have a two step process (read a line, then tokenize it) when you have a one step process (read a sequence of words)?

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