File.ReadAllLines(String) Method in C# with Examples
File.ReadAllLines(String) is an inbuilt File class method that is used to open a text file then reads all lines of the file into a string array and then closes the file.
public static string ReadAllLines (string path);
Parameter: This function accepts a parameter which is illustrated below:
- path: This is the specified file to open for reading.
- ArgumentException: The path is a zero-length string, contains only white space, or one or more invalid characters as defined by InvalidPathChars.
- ArgumentNullException: The path is null.
- PathTooLongException: The specified path, file name, or both exceed the system-defined maximum length.
- DirectoryNotFoundException: The specified path is invalid.
- IOException: An I/O error occurred while opening the file.
- UnauthorizedAccessException: The path specified a file that is read-only. OR this operation is not supported on the current platform. OR the path specified a directory. OR the caller does not have the required permission.
- FileNotFoundException: The file specified in the path was not found.
- NotSupportedException: The path is in an invalid format.
- SecurityException: The caller does not have the required permission.
Return Value: Returns a string array containing all lines of the file.
Below are the programs to illustrate the File.ReadAllLines(String) method.
Program 1: Initially, a file file.txt is created with some contents shown below-
GFG Geeks GeeksforGeeks
Program 2: Initially, no file was created. Below code itself create a file file.txt with some specified contents.
GFG is a CS portal.