Count the number of element present in the sequence in LINQ?
In LINQ, you can count the total number of elements present in the given sequence by using the Count Method. This method returns the total number of elements present in the given sequence.
This method can be overloaded in two different ways:
- Count<TSource>(): This method returns the total number of elements present in the given specified sequence. The return type of this method is System.Int32. This method gives ArgumentNullException if the source is null and OverflowException if the value of the source is large. It does not support query syntax in C#, but you can wrap the query into brackets() and use aggregation functions as shown in Example 1. It supports query syntax in VB.NET.
Syntax:
int Count<TSource>();
- Count<TSource>(Func<TSource, bool> predicate): This method is used to return the number of items which satisfy the given condition. The return type of this method is System.Int32. This method gives ArgumentNullException if the source or predicate is null and OverflowException if the value of the source is large.
Syntax:
int Count<TSource>(Func<TSource, bool> predicate);
Note: This method with predicate parameter is not supported in VB.NET.
Example 1:
// C# program to find total number of // elements present in the given array using System; using System.Linq; class GFG { // Main Method static public void Main() { // Data source int [] sequence = {6, 455, 50, 56, 102, 89, 9, 100, 67, 29}; // Display the sequence Console.WriteLine( "The sequence is: " ); foreach ( int s in sequence) { Console.WriteLine(s); } // Finding the total number of elements // present in the given sequence // Using Count function int result = sequence.Count(); Console.WriteLine( "Total number of Elements: {0}" , result); } } |
Output:
The sequence is: 6 455 50 56 102 89 9 100 67 29 Total number of Elements: 10
Example 2:
// C# program to count the total // number of the employees using System; using System.Linq; using System.Collections.Generic; // Employee details public class Employee { public int emp_id { get ; set ; } public string emp_name { get ; set ; } public string emp_gender { get ; set ; } public string emp_hire_date { get ; set ; } public int emp_salary { get ; set ; } } class GFG { // Main method static public void Main() { List<Employee> emp = new List<Employee>() { new Employee() { emp_id = 209, emp_name = "Anjita" , emp_gender = "Female" , emp_hire_date = "12/3/2017" , emp_salary = 20000 }, new Employee() { emp_id = 210, emp_name = "Soniya" , emp_gender = "Female" , emp_hire_date = "22/4/2018" , emp_salary = 30000 }, new Employee() { emp_id = 211, emp_name = "Rohit" , emp_gender = "Male" , emp_hire_date = "3/5/2016" , emp_salary = 40000 }, new Employee() { emp_id = 212, emp_name = "Supriya" , emp_gender = "Female" , emp_hire_date = "4/8/2017" , emp_salary = 40000 }, new Employee() { emp_id = 213, emp_name = "Anil" , emp_gender = "Male" , emp_hire_date = "12/1/2016" , emp_salary = 40000 }, new Employee() { emp_id = 214, emp_name = "Anju" , emp_gender = "Female" , emp_hire_date = "17/6/2015" , emp_salary = 50000 }, }; // Count the total number of employees // Using Count () method var res = ( from e in emp select e.emp_id) .Count(); Console.WriteLine( "Total number of Employees: {0}" , res); } } |
Output:
Total number of Employees: 6