Question

A class Names reads the following names from the .txt file

Name.txt

Jason Butler

Paul Cunningham

Logan Bryant

Cody paul

Robert Vernon Ehlers III

Quincy James Ellefson

Currionte Evans

Gavin Scott French

Zach Tyler Goss

Noah Cosby

Jeremy Whittle

Ryan brown

Jonah Dalton Null

Cameron jones

Xavier Rhodes

Malcom Wesley

Jamarcus johnson

Bernard smith

Joseph Nettles

Danny Willaims

James wellington

William bolar

Make a search directory using dynamic allocation where the user would search the any number of letters of the first name and the matching name/names would come up as output. Write C++ code and pseudocode in a doc file

Answer 1

In order to solve this problem, one should need to know about ifstream, eof, search, and npos.

• ifstream is a stream class that is used to read from external files.
• eof stands for End of File that is in simple terms, it checks till last value.
• search is either a function pointer or function object.
• npos is used to indicate no matches if the user wants to search for something.

Name.txt file:

C ++ Code for searching from a text file:

//basic header package to run the program
#include<iostream>
#include<conio.h>
//Name is in string, so add string package
#include<string>
// fstream package is used to run ifstream Myfile that is used to read the file
#include<fstream>

using namespace std;

int main()
{
    // search is itself a function object that is inbuilt
    string search;
    //offset is further used to manipulate or find the characters according to search input
    int offset;
    //line is itself a Name in text file
    std::string line;

    //ifstream is stream class to read from files, declaring filename that is Myfile
    ifstream Myfile;
    //opening the file that is Name.txt
    Myfile.open("Name.txt");
    //asking the user to enter the Name whatever they want to search
    cout<< "Type the name you want to search" <<endl;
    //storing the search value that the user input
    cin >> search;

    //if Name.txt file is open
    if(Myfile.is_open())
    {
    // eof stands for end of file that is in this case last name is the end of file
    while(!Myfile.eof())
    {
        //getline scans the value with space
        getline(Myfile, line);
        //if line.find is not equal to npos, this means name has been found
        if((offset = line.find(search, 0)) != string::npos){
            std::cout<< "The Name has been found as: " << line <<endl;
        }
    }
    //closing the Name.txt file
    Myfile.close();
    }
    else
    std::cout<<"Could not find the Name" << endl;
    //if search name doesn't match in Name.txt names, then system will pause for sometime
    system("PAUSE");
    return 0;

}

The output of the code if the user searches for the name Jason Butler:

so this is how one can search from a text file.