DataInputStream readDouble() method in Java with Examples Last Updated : 05 Jun, 2020 Comments Improve Suggest changes Like Article Like Report The readDouble() method of DataInputStream class in Java is used to read eight input bytes and returns a double value. This method reads the next eight bytes from the input stream and interprets it into double type and returns. Syntax: public final double readDouble() throws IOException Specified By: This method is specified by readDouble() method of DataInput interface. Parameters: This method does not accept any parameter. Return value: This method returns the double value interpreted by the next eight bytes of the input stream. Exceptions: EOFException - It throws EOFException if the input stream is ended before eight bytes can be read. IOException - This method throws IOException if the stream is closed or some other I/O error occurs. Below programs illustrate readDouble() method in DataInputStream class in IO package: Program 1: Assume the existence of file "demo.txt". Java // Java program to illustrate // DataInputStream readDouble() method import java.io.*; public class GFG { public static void main(String[] args) throws IOException { // Create double array double[] buf = { 10, 20, 30, 40, 50 }; // Create file output stream FileOutputStream outputStream = new FileOutputStream("c:\\demo.txt"); // Create data output stream DataOutputStream dataOutputStr = new DataOutputStream(outputStream); for (double b : buf) { // Write double value to // the dataOutputStream dataOutputStr.writeDouble(b); } dataOutputStr.flush(); // Create file input stream FileInputStream inputStream = new FileInputStream("c:\\demo.txt"); // Create data input stream DataInputStream dataInputStr = new DataInputStream(inputStream); while (dataInputStr.available() > 0) { // Print double values System.out.println( dataInputStr.readDouble()); } } } Output: Program 2: Assume the existence of file "demo.txt". Java // Java program to illustrate // DataInputStream readDouble() method import java.io.*; public class GFG { public static void main(String[] args) throws IOException { // Create double array double[] buf = { 10.9, 20.8, 30.88, 40.76, 50.678 }; // Create file output stream FileOutputStream outputStream = new FileOutputStream("c:\\demo.txt"); // Create data output stream DataOutputStream dataOutputStr = new DataOutputStream(outputStream); for (double b : buf) { // Write double value to // the dataOutputStream dataOutputStr.writeDouble(b); } dataOutputStr.flush(); // Create file input stream FileInputStream inputStream = new FileInputStream("c:\\demo.txt"); // Create data input stream DataInputStream dataInputStr = new DataInputStream(inputStream); while (dataInputStr.available() > 0) { // Print double values System.out.println( dataInputStr.readDouble()); } } } Output: References: https://docs.oracle.com/javase/10/docs/api/java/io/DataInputStream.html#readDouble() Comment More infoAdvertise with us P pp_pankaj Follow Improve Article Tags : Java Java-Functions Java-IO package Practice Tags : Java Similar Reads Java Tutorial Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems.Known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).Syntax and st 7 min read BasicsIntroduction to JavaJava is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. 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