Reading a File Where Some Have 2 Words

Howdy,

I am struggling with finding the best mode to read private words in a text file.
I tin can use getline to extract whole lines, but I need to pull out private words and store them in a cord array for comparison to another word. Overall it's just a word search plan.

Is there a simple way of reading words in C++ or do I have to accept it look at every character and detect spaces or something?

Thanks for the help!

The formatted extraction operator, >> , already does this. It reads until the next whitespace and skips any leading or trailing whitespace.

Terminal edited on

The operator >> skips only leading whitespace. It stops extracting when information technology reaches the end of a discussion.

I only ran into this issue myself, only I wish to have information technology ignore the whitespaces.

When you lot say 'ignore the whitespaces', this could mean one of many things - could you lot be more than specific? To me, >> already ignores whitepaces, just I assume this is not what you mean.

I mean I was attempting to grab the whole line, and not individual words. I didn't really intend to hijack the thread, though. It appears the OP wants to catch individual words, rather than whole lines. At that place must be something fundamentally dissimilar in how we've coded, resulting in us each applying the code in the wrong way.This is the code I have , which could very well be the solution he is looking for.

i 2 three four 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

using namespace std; int main() { cord r_content,w_content; fstream outfile; outfile.open up ("information.txt",ios_base::out); if (!outfile) { cout<<"Fault writing to file!"; return 0; } else { cout<<"Please enter a string to be written to the file:\northward"; cin>>w_content; cout<<"Writing to file...\n"; //send information to file earlier endmost outfile<<w_content; outfile.close(); } fstream infile; infile.open up("data.txt",ios_base::in); if (!infile) { cout<<"Error reading file!"; return 0; } else { cout<<"\nReading from file...\n"; //read data in before closing getline(infile,r_content); cout<<"The file contents are:\n"; cout<<r_content; infile.shut(); } }

                Please enter a string to exist written to the file: Hey You lot Writing to file...  Reading from file... The file contents are: Hey              

When I check the contents of information.txt manually, I observe that only Hey is present, and so I could exist wrong that the issue was my getline implementation. Rather, it appears to exist tied to cin. Changing line 15 to the following makes it work properly.
getline(cin,w_content);

                Please enter a string to be written to the file: Hey You Writing to file...  Reading from file... The file contents are: Hey You              

Then in the stop, I solved my own question. If Darth shows us some code, I'm sure we can nudge him in the right direction. I know that I've used getline to treat commas as delimeters, and put it in a loop to assign each word to it's own array position. Depending on the structure of his input file, this may or may not exist a applied solution, or you may wish to have it treat spaces the aforementioned way. Endeavor using getline like this within a loop:
getline(inputfilehandle,southward[i],' ');
where due south is an assortment of strings and i is the loop counter. If y'all are confused about the inputfilehandle part, take a await at how I used infile and outfile above.

Last edited on

And then it appears I demand to use >> . I will try that. Right now the code only uses getline to grab entire lines of text from a text file. So what I need is to figure out how to properly implement the >> operator in my code. Let me endeavour information technology and if I tin can't effigy it out I'll post my code.

Thanks for the help guys!

Some further experimentation reveals that calculation the ' ' to the third parameter makes it treat spaces equally delimeters.

Here's where I'm at...

1 ii 3 iv 5 6 7 eight 9 10 xi 12 13 14 15 16 17 xviii xix 20 21 22 23 24 25 26 27 28 29 30 31

#include <iostream> #include <fstream> #include <string> #include <sstream> using namespace std; int main() { string testline; string word; ifstream Test ( "TesterFile.txt" ); if ( !Examination.is_open() ) { cout << "There was a problem opening the file. Printing whatever fundamental to close." << endl; } while( Examination.practiced() ) { getline ( Test, testline ); cin >> testline; cout << testline << endl; } cin.ignore(); return 0; }

This is killing me, it's supposed to be function of a programme I fabricated that can search within docx files for keywords, and everything works except I can't read individual words in a text file I feel stupid!

How tin can I make this read an individual word? Right now the panel appears and just sits there, nothing displayed, doesn't seem to use a lot of memory or anything so I don't think it's an infinite loop or annihilation.

Ideas? I tried using .eof() and .proficient() in the loop, no luck.

Try changing line 22 to getline(Test,testline,' '); and encounter what happens.

EDIT: Actually information technology required some other change. Effort the change mentioned in a higher place, simply also remove line 23. Also, on line xv, you tin just use !Test as the status for your if statement.

Check out this code, adapted from yours.

ane ii iii 4 5 half-dozen 7 eight 9 10 xi 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 xxx 31 32 33 34 35 36 37 38 39 40

#include <iostream> #include <fstream> #include <cord> #include <sstream> #include <conio.h> using namespace std; int main() { string testline; cord word[16]; ifstream Exam ( "Data.txt" ); if (!Exam) { cout << "At that place was a trouble opening the file. Printing whatever cardinal to close.\n"; getch(); render 0; } int i=0; //store words in array while outputting, skipping blank lines while( Examination.good() ) { getline ( Examination, testline, ' '); if (testline!="") { word[i]=testline; cout << word[i] << endl; i++; } } //output whole array with spaces between each word cout<<"\nArray contents:\n"; for (int yard=0;g<i;k++) cout<<word[g]<<" "; return 0; }

My input file looks like this:

                Steven Seagal 1234 Post Drive Ventura, CA 90734  Adam Sandler 356 Golf game Street Calabasas, CA 92136              

and my output looked similar this:

                Steven Seagal 1234 Mail Drive Ventura, CA 90734  Adam Sandler 356 Golf Street Calabasas, CA 92136  Array contents: Steven Seagal 1234 Post Drive Ventura, CA 90734  Adam Sandler 356 Golf game Street Calabasas, CA 92136              

It's non perfect though, when outputting discussion[1] it outputted

and then more is needed to assistance it differentiate between words and numerical values, or it has to do with retentiveness of invisible newline characters. I'm going to be looking into this farther.

Last edited on

why non just use:

1 2 3

ifstream file("the_file.whatever"); while(file >> some_string) some_vector_of_type_string.push_back(some_string);

? it grabs whitespace seperated words

If you use getline with ' ' as the delimiter, it will not skip multiple spaces and it will keep other forms of whitespace that >> would normally skip.

This would explain a lot about my plan'south beliefs. Upon modification, I realized that some values, despite existence outputted, were not properly being stored. I changed the assortment output loop at the end to

i 2 3

cout<<"\nArray contents:\n"; for (int i=0;i<11;i++) cout<<word[i]<<"("<<i<<")"<<endl;

hoping to display each assortment position's string. Not only did some entries output to multiple lines, only some values such every bit the start zippo code, were never stored. If y'all output

it is the CA from the first address, yet when outputting

it but displays Adam.

I tried making changes as suggested to a higher place, just it merely fabricated things worse.

1 two three 4 five half dozen vii 8 9 10 11 12 13 14 15 sixteen 17 eighteen 19 20 21 22 23 24 25 26 27 28 29 xxx 31 32 33 34 35

#include <iostream> #include <fstream> #include <string> #include <sstream> #include <conio.h> #include <vector> using namespace std; int main() { string testline; vector<string> discussion; ifstream Test ( "Data.txt" ); if (!Test) { cout << "There was a trouble opening the file. Press whatsoever fundamental to close.\n"; getch(); return 0; } //store words in array while outputting, skipping blank lines while( Examination>>testline ) { getline ( Exam, testline, ' '); cout<<testline; give-and-take.push_back(testline); } //output whole assortment with spaces between each discussion cout<<"\nArray contents:\n"; for (int i=0;i<word.size();i++) cout<<word[i]<<"("<<i<<")"<<endl; return 0; }

                                  1234 Ventura,  Adam 356 Calabasas,92136 Array contents: (0)  1234(1) (2)  Ventura,(3) (iv)   Adam(5)  356(6) (7)  Calabasas,(8) (nine) 92136(10)              

Irresolute the status of the while loop to merely be Examination on line 25 results in closer to the desired output, yet withal displays some oddities.

                Steven Seagal 1234 Postal service Drive Ventura, CA 90734  Adam Sandler 356 Golf game Street Calabasas, CA 92136 92136  Array contents: Steven(0) Seagal 1234(one) Post(2) Drive Ventura,(3) CA(4) 90734  Adam(five) Sandler 356(6) Golf(7) Street Calabasas,(eight) CA(9) 92136(10) 92136(11)                              

I take two questions:
#one. Why does it output and store the concluding nothing code twice when reading it in?
#2. Why are multiple strings beingness combined into single entries? (I assume information technology has something to exercise with newline characters, but am unsure). Outputting

gives me

at present.
Withal I wish to store the information as 16 differing entries, not 12, and without the back-up of storing zippo codes twice.

Terminal edited on

I got it mostly solved now. LB was right all along most the utilize of >> , it really is key to reading in private words.

1 2 3 4 5 6 7 viii 9 10 11 12 xiii 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 thirty 31 32 33 34 35 36

#include <iostream> #include <fstream> #include <string> #include <sstream> #include <conio.h> #include <vector> using namespace std; int principal() { string testline; vector<string> discussion; ifstream Test ( "Information.txt" ); if (!Examination) { cout << "There was a problem opening the file. Press whatever fundamental to close.\northward"; getch(); return 0; } //shop words in assortment while outputting while( Test ) { Test>>testline; cout<<testline<<endl; word.push_back(testline); } //output whole assortment with array position numbers for each entry cout<<"\nArray contents:\n"; for (int i=0;i<give-and-take.size();i++) cout<<word[i]<<"("<<i<<")"<<endl; return 0; }

                Array contents: Steven(0) Seagal(1) 1234(2) Post(3) Drive(four) Ventura,(v) CA(6) 90734(7) Adam(8) Sandler(9) 356(x) Golf(eleven) Street(12) Calabasas,(13) CA(fourteen) 92136(xv) 92136(xvi)              

Why is it storing the final value twice? Other than that, this code should demonstrate how to collect individual words from file input.

EDIT: Problem solved. I changed the condition of the while loop on line 24 to !Examination.eof() and this prevented the terminal entry being stored twice. Using the above code with that change should permit you lot to read any entries inside a text file to an array or vector of strings. If choosing to go with an array, use word[i]=testline; with i as a counter, instead of push_back within of the while loop. Just and then you know Darth, the console window was awaiting input considering of line 23 in the code you posted last.

Last edited on

CplusplusAcolyte wrote:
Why is it storing the last value twice?

Because your loop condition is incorrect:

23 24 25 26 27 28 29

//store words in assortment while outputting while( Exam ) { Test>>testline; cout<<testline<<endl; word.push_back(testline); }

When you read the last bytes of a file, it does not ready whatsoever eof or bad flags, so the stream is still in good country, significant yous run the loop an actress fourth dimension. On this extra time, the input performance fails, leaving 'testline' unchanged, and then since you don't care that it failed, y'all push it onto the vector again. E'er perform input in the loop condition:

24 25 26 27 28

while(Test >> testline) { cout << testline << endl; discussion.push_back(testline); }

CplusplusAcolyte wrote:
EDIT: Trouble solved. I inverse the condition of the while loop on line 26 to !Exam.eof() and this prevented the final entry being stored twice.

No, it didn't, you just got lucky. Never loop on eof.

Last edited on

Thanks LB, that explained a lot. So my before attempt in using the loop the way you take shown didn't piece of work considering I included my redundant older attempt to read words into the string.

1 2 3 4 5

while(Test >> testline) { cout << testline << endl; word.push_back(testline); }

is much simpler. While I hadn't heard that loop conditions based on eof were bad do, I like this solution better anyway, and it greatly simplified my code.

1 2 3 iv 5 6 7 8 ix 10 11 12 13 14 15 sixteen 17 18 19 20 21 22 23 24 25 26 27 28 29 30

#include <iostream> #include <fstream> #include <string> #include <vector> using namespace std; int main() { string testline; vector<string> word; ifstream Test ( "Data.txt" ); if (!Exam) { cout << "There was an error opening the file.\northward"; render 0; } //store words in vector while( Exam>>testline ) word.push_back(testline); //output whole vector with position numbers for each entry cout<<"Array contents:\n"; for (int i=0;i<word.size();i++) cout<<word[i]<<"("<<i<<")"<<endl; return 0; }

Would you similarly say that looping based on vector size was bad practice, or is this determination limited to eof?

Concluding edited on

Tin can't thank you guys plenty! I'thou learning a lot hither.

I don't understand vectors, I'1000 all the same a noob and it wasn't covered in the class I took. Later some googling, my understanding is a vector is essentially a dynamic array... Is that right? And what does push_back() practice?

Can I utilize strcmp with a vector that's a string type?

Thanks again for all the aid I really capeesh it!

You are right, a vector is like to an array, except the size does non need to exist known. push_back(testline) adds testline to the last position in the vector, and is similar to array[i]=testline; , although with an array, you demand to know what position you are adding it to and make use of a loop to control the value of i.

The code below does the aforementioned thing, but stores the values in an assortment then you can see the difference. Yous will see that we had to declare how many values the array holds, and had to base our output loop on the size of the array.

An array cannot have values added to information technology beyond the number specified at declaration, wheras a vector can have additional entries added through the utilize of push_back , and doesn't need to know how many values it will agree. Lastly, a vector allows us to output without knowing the number of values by using vectorname.size() in the output loop.

1 2 iii iv 5 6 7 eight nine ten xi 12 13 14 fifteen xvi 17 xviii 19 twenty 21 22 23 24 25 26 27 28 29 30 31 32 33 34

#include <iostream> #include <fstream> #include <string> #include <vector> using namespace std; int main() { cord testline; cord word[16]; ifstream Test ( "Data.txt" ); if (!Test) { cout << "In that location was an error opening the file.\n"; render 0; } //store words in array int i=0; while( Test>>testline ) { word[i]=testline; i++; } //output whole assortment with assortment position numbers for each entry cout<<"Assortment contents:\n"; for (int i=0;i<sixteen;i++) cout<<give-and-take[i]<<"("<<i<<")"<<endl; return 0; }

Terminal edited on

CplusplusAcolyte wrote:
Would yous similarly say that looping based on vector size was bad practice, or is this determination limited to eof?

Yep, I would similarly say that looping on vector size is bad practice. Utilize iterators instead, or the range-based for-loop when possible.

I suppose I'm yet learning the use of iterators, equally vectors are fairly new to me and I found this usage simpler. I'll explore this outcome further in another thread if I accept trouble grasping it. Thanks for all the feedback, LB. It helped me a lot, and likely benefited Darth as well.

Last edited on

Topic archived. No new replies allowed.

riveraofas1947.blogspot.com

Source: https://www.cplusplus.com/forum/beginner/121657/

Share this post