How read this file into array without comma?

This is a discussion on How read this file into array without comma? within the C++ Programming forums, part of the General Programming Boards category; Hello all: My program need to read files with numbers as: 1,171.11 1,159.36 1,154.05 Because these numbers can not be ...

  1. #1
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    Question How read this file into array without comma?

    Hello all:

    My program need to read files with numbers as:
    1,171.11
    1,159.36
    1,154.05

    Because these numbers can not be calculated in C/C++, I need to store then in the arrays as:
    1171.11
    1159.36
    1154.05
    that is without commas.

    How read numbers in a file into program arrays taking away commas?

    Could you help me?

  2. #2
    ^ Read Backwards^
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    Code:
    #include <iostream>
    #include <string>
    using namespace std;
    
    
    int main()
    {
    
    	string example; 
    	example = "123,456.00";
    
    	int pos;
    
    	pos = example.find(',',0); //Searches for "," in string starting at position 0
    						 
    												 
    	/* If the string does not have the char in it, then there is nothing to delete
    	This only deletes if the 'not found' value is not present */
    	
    	if ( pos != string::npos) 
    	{
    
    	example.erase(pos,1); //Erases from string, starting at position pos (returned by search)
    	}
    
    
    	cout << example;
    
      return 0;
    }
    For more info on using strings (which are arrays):
    http://www.msoe.edu/eecs/ce/courseinfo/stl/string.htm

    This will only find the first occurrence of the comma, so if you might have more than one comma (such as 123,456,789.00) you can just put it in a loop.
    Last edited by Enahs; 09-30-2005 at 08:08 AM.

  3. #3
    Super Moderater.
    Join Date
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    This isn't perhaps the prettiest example but it serves your purpose. Be careful of the EOF. Best to avoid using it if you can.

    Code:
    #include <fstream>
    #include <iostream>
    #include <string>
    using namespace std;
    
    int main()
    {
        /*
        list.txt
        -----------------
        1,171.11
        1,159.36
        1,154.05
        */
        
        fstream file_pointer;
        file_pointer.open("list.txt",ios::in);
        
        do
        {
            char array[81];
            char barray[81];
            file_pointer>>array;
            
            int size = strlen(array);
            int count=0;
            int i;
            for( i=0; i<size; i++)
            {
                if (array[i]!=',')
                {
                    barray[count]=array[i];
                    count++;
                } 
            }
            barray[i-1]='\0';//get rid of the junk which may be present
            float f;
            f=atof(barray); //convert to float
            cout<<f;//you can now perform standard maths on the number
            //cout<<f*2;
            cin.get();
            count=0;        
             
                }while(file_pointer.peek()!=EOF);
                file_pointer.close();
    }

  4. #4
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    Man...whatever happened to the days of giving the OP some advice and letting him/her figure it out?
    If I did your homework for you, then you might pass your class without learning how to write a program like this. Then you might graduate and get your degree without learning how to write a program like this. You might become a professional programmer without knowing how to write a program like this. Someday you might work on a project with me without knowing how to write a program like this. Then I would have to do you serious bodily harm. - Jack Klein

  5. #5
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    Question Re:How read this file into array without comma?

    Hello Enahs and Treenef:

    Thank you for your passionate responses to write the program for me. Could you go a step forward to modify your program with following requirements.

    Suppose the file named file.txt contains numbers:
    1,111.11
    2,222.22
    3,333.33
    After reading these numbers and then write them into a new file named file_new.txt, the numbers in new file changed to:
    1111.11
    2222.22
    3333.33

    It means that the numbers in file.txt with commas, but in file_new.txt without commas.

    Could you help again?

  6. #6
    and the hat of wrongness Salem's Avatar
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    > Could you go a step forward to modify your program with following requirements.
    Get off your lazy arse and do some bloody work yourself
    Just how much of a spoon-feed do you need?????
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  7. #7
    Unregistered User
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    oh come on, he will make a good IT manager some day!

  8. #8
    Registered User
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    Ok now you're just being lazy. Go look at the string functions on msdn.

  9. #9
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    Thumbs up Solved

    Now Everything has been solved. Thanks anyway.

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