Counting the words in a string C++

This is a discussion on Counting the words in a string C++ within the C++ Programming forums, part of the General Programming Boards category; Code: #include <iostream> #include <string> using namespace std; int wordcount(char *str){ int i=0; int count=0; while(&str[i] != "

Thread: Counting the words in a string C++

"){ if(&str[i] == ...

  1. #1
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    Question Counting the words in a string C++

    Code:
    #include <iostream>
    #include <string>
    using namespace std;
    
    int wordcount(char *str){
        int i=0;
        int count=0;
    while(&str[i] != "\0"){
        if(&str[i] == "\t"){
            count++;}
       i++;
    }
    return count;
    }
    
    
    int main()
    {
       string stringA;
       cout<<"Insert a string"<<endl;
       cin>>stringA;
       cout<<"there are"<<wordcount(stringA)<<"words in your string";
    }
    This is my code.The problem is i get an error on the last line saying:

    "Cannot convert 'std::string' to 'char' for argument '1' to 'int wordcount(char*)' "

    Im really stuck here, pls help .
    Any help is apreciated.Thanks

    Edit:Oups i posted in thw rong section.Sorry!
    Last edited by mblue; 03-30-2009 at 12:38 PM.

  2. #2
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    You are passing a std::string, to a function which takes a char*. You should pass the parameter as stringA.c_str().

    Also you would need to change the wordcount signature to take a const char* instead of just a char* (since the c_str() function returns a const char*).

    Also, your char comparisons wont work as they stand. Instead of
    Code:
    &str[i] != "\0"
    it should be
    Code:
    str[i] != '\0'
    .

    Finally, please properly format your code before pasting it here. Look how much easier it is to read when it's formatted:
    Code:
    int wordcount(char *str)
    {
        int i=0;
        int count=0;
        while(&str[i] != "\0")
        {
            if(&str[i] == "\t")
            {
                count++;
            }
            i++;
        }
        return count;
    }

  3. #3
    C++ Witch laserlight's Avatar
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    You made the right choice by using std::string, so why do you provide a char* parameter for your wordcount function?
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  4. #4
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    1. &str[i] == "somestring" will never be true. You should compare a single character, not pointers to strings. To use a character in stead of a string, use '\0', for instance, in stead of "\0".
    2. the "char *str" argument to wordcount should be "const char *" since it won't change it.
    3. You can't pass a string to a char*. To convert it to a const char*, use somestring.c_str().

  5. #5
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    the conditions "\t" and "\0"should maybe be '\t' and '\0'instead. i dont know c++ but it looks like you compare two strings togheter here
    PHP Code:
     while(&str[i] != "\0"){ 
    what i am sure is not right.

  6. #6
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    Ok, i understand that i made a function that takes a char as argument and im trying to use it on a string.That wont work.
    What should i do now?Modify the function so that it takes a string as argument or turn the string into char and then pass it to the function?

    I forgot to tell you that im a newb in c/c++.
    Ive got a headache already.lol

  7. #7
    "I Win!" by U. Lose vart's Avatar
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    This is C++ - why do you post on C-forum?
    Why do you pass std::string to the function expecting C-string?
    Why do you write function that manipulates C-string - use std::String directly
    To be or not to be == true

  8. #8
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    There is a post in the C++ forum AS WELL. Maybe one of the mods can merge or lock this thread with a link to the other one.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  9. #9
    C++ Witch laserlight's Avatar
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    Quote Originally Posted by matsp
    There is a post in the C++ forum AS WELL. Maybe one of the mods can merge or lock this thread with a link to the other one.
    Right, and merged.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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