File length() method in Java with Examples

The length() function is a part of File class in Java . This function returns the length of the file denoted by the this abstract pathname was length.The function returns long value which represents the number of bytes else returns 0L if the file does not exists or if an exception occurs. 

Function signature:

public long length()

Syntax:

long var = file.length();

Parameters: This method does not accept any parameter. 

Return Type The function returns long data type that represents the length of the file in bits. 

Exception: This method throws Security Exception if the write access to the file is denied Below programs illustrate the use of the length() function: 

Example 1: The file "F:\\program.txt" is an existing file in F: Directory. 

// Java program to demonstrate
// length() method of File Class

import java.io.*;

public class solution {
    public static void main(String args[])
    {

        // Get the file
        File f = new File("F:\\program.txt");

        // Get the length of the file
        System.out.println("length: " + f.length());
    }
}

Output:

length: 100000

Example 2: The file "F:\\program1.txt" is empty 

// Java program to demonstrate
// length() method of File Class

import java.io.*;

public class solution {
    public static void main(String args[])
    {

        // Get the file
        File f = new File("F:\\program.txt");

        // Get the length of the file
        System.out.println("length: " + f.length());
    }
}

Output:

length: 0

Note: The programs might not run in an online IDE. Please use an offline IDE and set the path of the file.