File.ReadLines(String) Method in C# with Examples Last Updated : 01 Jun, 2020 Comments Improve Suggest changes Like Article Like Report File.ReadLines(String) is an inbuilt File class method that is used to read the lines of a file. Syntax: public static System.Collections.Generic.IEnumerable ReadLines (string path); Parameter: This function accepts a parameter which is illustrated below: path: This is the specified file for reading. Exceptions: ArgumentException: The path is a zero-length string, contains only white space, or one or more invalid characters defined by the GetInvalidPathChars() method. ArgumentNullException: The path is null. DirectoryNotFoundException: The path is invalid. FileNotFoundException: The file specified by the path was not found. IOException: An I/O error occurred while opening the file. PathTooLongException: The path exceeds the system-defined maximum length. SecurityException: The caller does not have the required permission. UnauthorizedAccessException: The path specifies a file that is read-only. OR this operation is not supported on the current platform. OR the path is a directory. OR the caller does not have the required permission. Return Value: Returns all the lines of the specified file. Below are the programs to illustrate the File.ReadLines(String) method. Program 1: Initially, a file file.txt is created with some contents shown below- CSharp // C# program to illustrate the usage // of File.ReadLines(String) method // Using System and System.IO namespaces using System; using System.IO; public class GFG { public static void Main(String[] argv) { // Calling the ReadLines(String) function foreach(string line in File.ReadLines(@"file.txt")) { // Printing the file contents Console.WriteLine(line); } } } Output: GFG gfg Geeks GeeksforGeeks geeksforgeeks Program 2: Initially, a file file.txt is created with some contents shown below- Below code filter some contents from the file and prints them back. CSharp // C# program to illustrate the usage // of File.ReadLines(String) method // Using System and System.IO namespaces using System; using System.IO; public class GFG { public static void Main(String[] argv) { // Calling the ReadLines(String) function foreach(string line in File.ReadLines(@"file.txt")) { // Filtering the file contents and printing if (line.Contains("GFG")) { Console.WriteLine(line); } } } } Output: GFG Comment More infoAdvertise with us Next Article File.ReadLines(String) Method in C# with Examples K Kanchan_Ray Follow Improve Article Tags : C# CSharp-File-Handling Similar Reads C# Tutorial C# (pronounced "C-sharp") is a modern, versatile, object-oriented programming language developed by Microsoft in 2000 that runs on the .NET Framework. 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