contains method

thank you for your answer
is there any possibility to give the field to check wheather the list contains the object of that field in the contains function itself

Hi Srinivas,

I found the solution for you.


You should write your employee class as follows. Focus on the lines in red.



    public class Employee : IEquatable
    {
        public string name;
        public int age;

        public override bool Equals(object obj)
        {
            return this.Equals(obj as Employee);
        }

        public bool Equals(Employee p)
        {
            // If parameter is null, return false.
            if (Object.ReferenceEquals(p, null))
            {
                return false;
            }

            // Optimization for a common success case.
            if (Object.ReferenceEquals(this, p))
            {
                return true;
            }

            // If run-time types are not exactly the same, return false.
            if (this.GetType() != p.GetType())
                return false;

            return (name == p.name);//Here, if names are equals return true.
        }

    }


That means, I wrote a value equality for the employee. If the names are same of two employee objects it will return true for Equals method.


Now you can  use Contains method.


            Employee a = new Employee();
            a.name = "abc";
            a.age = 18;

            Employee b = new Employee();
            b.name = "sdf";
            b.age = 18;

            List v = new List();
            v.Add(a);

            if (v.Contains(b)) //If b has the same name as a it will return true. Otherwise false.
            {
            }


If you have any problem let me know pls.


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how to implement /use that extension method in my program. is there any possible to use that method please help me
 

ok thank you I got it
do you know about the extension method of contains
 

using System;
using System.Collections.ObjectModel;
using System.Collections.Generic;
using System.Linq;
using System.Text;
//this is my class
public class LibraryClass
    {
        #region Fields
        int bookId;
        string bookName;
        string category;
        string authorName;
        #endregion
        #region Properties
        public int BookId
        {
            get { return bookId; }
            set { bookId = value; }
        }
        public string BookName
        {
            get { return bookName; }
            set { bookName = value; }
        }
        public string Category
        {
            get { return category; }
            set { category = value; }
        }
        public string AuthorName
        {
            get { return authorName; }
            set { authorName = value; }
        }
        #endregion
        public LibraryClass()
        {
        }
        public LibraryClass(int a,string b,string c,string d)
        {
            this.BookId = a;
            this.BookName = b;
            this.category = c;
            this.AuthorName = d;
        }
        public override string ToString()
        {
            return string.Format("{0,-5}{1,-10}{2,-10}{3,-10}", BookId, BookName, Category, AuthorName);
        }
    }

class Program
    {
        static void Main(string[] args)
        {
            LinkedList obj = new LinkedList();
            obj.AddFirst(new LibraryClass(10,"srinivas","fds","dsffdsf"));
            obj.AddFirst(new LibraryClass(20, "srini", "ffds", "ddsfsffdsf"));
            obj.AddFirst(new LibraryClass(30, "sriniffsf", "ffdfsfds", "dfdsdsfsffdsf"));
            foreach (LibraryClass val in obj)
            {
                Console.WriteLine(val);
            }
now i have to know wheather obj linkedlist has an Library class object with BookName="srinivas"
to know this how to write the Contains method
 
        }
    }

i have to use contains method for LinkedList
that is iam storing my employe objects in ths linkedlist and now using Contains method how to know my linkedlist has an object which has the name="xyz"
i think you understood my problem
plz help me for this
thank you