write a program to Finding words that begin with specific letter "s" in text file.

[kuldeep s]

Hi Experts,

Question about File handling in C++ ....

write a program to Finding all words that begin with specific letter "s" in text file?

[keskiverto]

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File I/O is no different from other I/O; the standard library has the stream abstraction:
http://www.cplusplus.com/doc/tutorial/files/

WHILE read word from stream
  IF word starts with s
  THEN do something

[kuldeep s]

plz help, this program is very important for me.

[tpb]

plz help, this program is very important for me.

It's a pretty easy program. If you can't write it then maybe it's best that you fail the course. If you've made an attempt then post your code and we can help you fix it.

[MikeyBoy]

plz help, this program is very important for me.

We would love to help you fix your code. But we can't, if you don't show us your code.

[kuldeep s]

#include <iostream>
#include <fstream>
using namespace std;

int main () {
ifstream input;
string filename="file.txt";
string word;

input.open(filename.c_str());
int len=word.length();

while(getline(input,word)) {

if(word.at(len-1)='a') {
cout<<word;
}

}
}

[Ganado]

try if (word.length() > 0 && word.at(0) == 'a') instead.

Notice that it's == (equality), not = (assignment).

[kuldeep s]

showing blank output...

[doug4]

Notice that you declare "word" in line...um let me count...8 (always post your code within code tags--click the "<>" format button to create the tags and paste your code in between them).

Then in line 11, while word is still empty, you save the "len", which, because word is empty, has a value of 0.

In line 13 you start looping through the file and reading each line and assigning it to "word". You never recalculate the value "len", so it is always 0. Because of that the

if (word.length() > 0 && word.at(0) == 'a') statement will always fail, and you will never print out a word.

[Ganado]

kuldeep wrote:

showing blank output...

Gee, I sure wish I were psychic, to know what you actually changed!

#include <iostream>
#include <fstream>
using namespace std;

int main () {
    ifstream input;
    string filename="file.txt";
    string word;

    input.open(filename.c_str());
    int len=word.length(); // useless

    while(getline(input,word)) {

        //if(word.at(len-1)='a')
        if (word.length() > 0 && word.at(0) == 'a') 
        {
            cout<<word;
        }

    }
}

input:

aardvark
apple
banana
anana
nana
nani???

output:

aardvarkappleanana

Obviously the above can be cleaned up more. I just changed the one line to prove that what I said does work.

PS: If you're delimiting based on words and not lines, use operator>>(std::istream&, std::string) and not std::getline.

[kuldeep s]

but i am giving input in given below format then after it is not working:

aardvark apple banana anana nana nani???

[Ganado]

Those aren't lines! Your own post had you using getline. Use input >> variable; to extract tokens delimited by whitespace.

[Karakuik]

Why not just read it char by char? You'd surely find an S that way

[kuldeep s]

Thank you so much "Ganado" sir.....