Difference between revisions of "Java/C2/User-Input/English-timed"

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Revision as of 15:21, 26 June 2013

Time' Narration
00:02 Welcome to the spoken-tutorial on Taking user input in Java using BufferedReader .
00:09 In this tutorial we will learn:
00:11 To take user input in Java
00:13 About InputStreamReader and BufferedReader


00:17 To follow this tutorial you must know:
00:19 how to write, compile and run a simple java program in Eclipse
00:24 You must also know the about the datatypes in Java
00:27 If not, please refer to the spoken tutorial on these topics available at spoken hyphen tutorial dot org.


00:35 Here, I am using,

Ubuntu v 11.04

JDK 1.6 and

Eclipse IDE 3.7.0

00:44 Now, we will learn what a BufferedReader is.
00:48 It is a class which is used to read text from an input stream.
00:53 It provides efficient way to read array of characters and lines.


00:59 To make use of BufferedReader , we need to import three classes' from the java dot io package.
01:05 These three classes are:
  • IOException
  • InputStreamReader and
  • BufferedReader
01:12 We will learn about packages and how to import classes in the coming tutorials.
01:18 Now how is the input taken.
01:21 All the input that we take from the user will be in the form of String.
01:26 It has to be then typecasted or converted to the particular datatype.
01:31 We will see that while we write our program to take the user input.
01:35 Now, let us see the syntax to implement BufferedReader.
01:39 Once you import the three classes, you need to create an object of InputStreamReader.
01:45 You also need to create an object of BufferedReasder.
01:49 We will learn about this in detail, when we write our program.
01:54 So, let us switch to Eclipse.
01:56 I have already opened a class named InputBufferedReader.
02:00 We will begin with importing the java.io package.


02:04 So type, before the class import space java dot io dot star semi colon.
02:14 This will import the classes InputStreamReader, BufferedReader and IOException.


02:20 Now We will make use of BufferedReader inside the main method.
02:25 We need to throw an IOException in whatever method we use the BufferedReader.
02:31 So right after the main method type throws IOException.
02:42 Now, what does this mean?
02:45 Exceptions are errors which occur in Java when some unexpected circumstances occur.
02:52 To prevent Exception errors we make use of throws keyword.
02:57 Throws is a keyword which is used during Exception handling.
03:00 It is used whenever we know that Exception error will definitely occur.
03:05 When we use BufferedReader, exception error always take place.
03:10 To prevent Exception errors from taking place we make use of throws IOException.
03:16 We will learn about Exception Handling in the coming tutorials.
03:20 Now, we will create an object of InputStreamReader.
03:24 For that, inside the main method type InputStreamReader space isr equalto new space InputStreamReader parentheses.
03:44 Within parentheses, type System dot in and then semicolon.
03:52 InputStreamReader is a class in javawhich allows us to take the user input .
04:01 System dot intells the java compiler to take the input from the user using keyboard.
04:10 The input that System dot in takes is stored in the object of InputStreamReader for sometime.
04:17 After this we create an object of BufferedReader.
04:22 So type, BufferedReader br equal to new space BufferedReader and then parentheses.
04:36 Inside the parentheses, type the object of InputStreamReader which is isr.
04:43 Now, isr only helps to take the input from the user.
04:48 BufferedReader helps to store the value in the BufferedReader object.
04:54 Isr passes this value to the BufferedReader object to store it.
05:01 Now, let us start taking input from the user.
05:06 We will first ask the user to enter a String. So create a variable of String type


05:14 Type, String space str semicolon
05:19 Now ask the user to enter his name.
05:23 So type, System dot out dot println within brackets and double quotes Enter your nameand thensemicolon.
05:33 To take the input as String we will type.
05:37 str equal to br dot readLine parentheses and then semicolon.
05:45 The readLine method will read the input from the user .
05:51 Now, let us take the input as an integer. Create a variable of typeint.
06:01 So type int n semicolon.
06:05 Ask the user to enter his age.
06:08 So Type, System dot out dot println within brackets and double quotes Enter your age semicolon.


06:21 Also, create another variable named str1 of String type in order to take the input.


06:31 Now to take the input as String, type str1 equal to br dot readLine parentheses and then semicolon.
06:45 To convert it into integer datatype, type n equal to Integer dot parseInt within brackets str1semicolon
07:05 Integer is a class and parseInt is its method.
07:11 This method converts the argument passed within the bracket into integer.
07:18 Now, let us display the output for name and age.
07:22 So, type System dot out dot println within brackets and double quotes The name is plus str semicolon.
07:38 Next line type, System dot out dot println The ages plus n and thensemicolon.
07:50 Now, Save the file, press Ctrl, Skeys. Now let us run the program
07:55 So press Control and F11 keys.
08:00 In the output, you are asked to Enter your name.
08:03 So type your name. I will type here Ramu press Enter.
08:08 You will be asked to enter your age.
08:11 I will type here20 and then press Enter
08:13 We get the output as :
08:15 The name is Ramu
08:16 And The age is 20.
08:18 Thus we know how to take an input from the user.
08:24 In this tutorial we have learnt :
08:26 About InputStreamReader
08:28 About BufferedReader
08:29 And Converting from String to the desired datatype


08:33 For self-assessment, take a float, byte and character input from the user and then display the output
08:42 Also take a number as input and divide it by 3 then Display the output on the console.
08:49 To know more about the spoken tutorial project;Watch the video available at the following link
08:54 It summarises the Spoken Tutorial project
08:57 If you do not have good bandwidth, you can download and watch it
09:02 The Spoken Tutorial Project Team
09:04 Conducts workshops using spoken tutorials
09:07 Gives certificates to those who pass an online test
09:11 For more details, please write to contact@spoken-tutorial.org
09:18 Spoken Tutorial Project is a part of the Talk to a Teacher project
09:21 It is supported by the National Mission on Education through ICT, MHRD, Government of India
09:27 More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro
09:36 This is Arya Ratish from IIT Bombay.

Thank You for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14, Sneha