Difference between revisions of "Java/C2/First-Java-Program/English-timed"

|| In this tutorial we will learn  

| To create a simple Java program.  

| To compile the program.

| To run the program.  and

| About the naming conventions followed in Java

|  Here we are using '''Ubuntu version 11.10''' and '''jdk 1.6'''

|If not, for relevant tutorial please visit our website which is as shown.

|Alright now let us   write our first Java program.

|For that you need a '''Terminal''' and you need  a '''Text''' '''Editor'''.

| I am using '''gedit''' as my '''Text Editor'''  

|  In the '''text editor'''   , we will first create the class '''HelloWorld'''.  

|So type class '''HelloWorld'''. '''HelloWorld '''is the name of the class.

| And   Open '''curly bracket'''.  '''Enter''' and close '''curly bracket'''.

|  The code between this two curly brackets  will belong to the class '''HelloWorld'''

|  Now save the file by clicking on '''Save '''icon at the top  

|  Here, in the home directory i will create a folder.

|Let us name it   '''Demo''' and press ''' enter'''

|Then inside this folder we will save the file.

| In the '''Name''' text-box, type the name of the class.

|Recall that we  created  class   HelloWorld.

|So we will save the file   as''' HelloWorld dot java'''

|  '''Dot''' Java is the file extension  given to the Java file.

| Inside the class, we write the '''main''' method.  

|'''''public static void main '''  ''parentheses'' inside  ''parentheses'' '''String''' '''arg''' Square brackets''  

|'''Main''' functions marks the starting point of the program.

|We will describe '''public, static, void and String ''' in a future tutorial.

|Then  once again, open curly bracket.

|Press '''Enter '''and close curly bracket.

|  The code between these two curly brackets will belong to the main method.

|So inside main method  type'''''System '''dot''' out '''dot''' println''''' parentheses semi-colon

|This is the statement used to print a line.    

|Now let us tell Java, what to print.

| So Within '''parentheses in double quotes type, My first java program exclamation mark'''.

|  Let us '''Save'''the file by clicking on '''Save''' icon.

|  Let's go   to '''Terminal'''.

|Make sure that you are in the directory where  you save your  '''HelloWorld.java'''  

|Remember that I am in my home directory.

|So''''' '''''type''''' cd '''Space''' Demo '''''and''''' '''hit''' Enter'''''

|We see  ''' HelloWorld.java''' file present in the Demo folder.

| Lets compile this file so type   '''javac '''Space''' HelloWorld '''dot''' java''''' and hit''' enter'''  

|This   compile the file that we have created.  

|  Alright now the file is compiled as we see no error.

|That is, on any '''Operating System. '''

| So After successful compilation, run the program using the command,  

|'''''java '''''(This time no c) space '''''HelloWorld '''''(and no dot java extension) and hit '''Enter'''.

|  For    Example: showString(), main(), goToHelp(). Here '''s''' of show is in lowercase while  '''S''' of string is in uppercase  

|The variable name should not begin with '''digits''' .  

| We cannot use keywords for our '''class, method or variable name'''.

|For example:  cannot use keywords like''' public, private, void, static and many more'''.  

|For self assessment write a simple java program to print '''Java file name and class name should be same'''.

|To know more about the Spoken Tutorial Project

|  Watch the video available at [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]  

| It summarises the Spoken Tutorial project  

| If you do not have good bandwidth, you can download and watch it  

|  The Spoken Tutorial Project Team

| Conducts workshops using spoken tutorials  

|Gives certificates to those who pass an online test  

|  Spoken Tutorial Project is a part of the Talk to a Teacher project  

|It is supported by the National Mission on Education through ICT, MHRD, Government of India  

| More information on this Mission is available at  

 

[http://spoken-tutorial.org/NMEICT-Intro]  

|This is Prathamesh Salunke signing off.  Jai Hind.