How to compile java file on cmd using javac command in Windows??

How to compile java file on cmd using javac command in Windows??

Step1:  First navigate to:

MyComputer -> Local Disk(C:) -> ProgramFiles -> Java - > jdk -> bin 

Now you will see a file named javac.exe in bin folder.

Step2: Now Copy the path of this folder and paste it on the notepad.

  NOTE: During the first Eight steps it should be taken care that your command prompt should not be open. If it is open close it first or else the changes might not be reflected in your command prompt.

Step3: Start -> Computer -> RightClick -> Properties

  Step 4: Now click on Advanced system settings

Step 5: Click on Environment Variables

Step6: Click on new.

Step 7: Now enter the name “PATH” and in value paste the path that was copied in Step 2 And Click OK

Step 8: You will see the variable path in the box. Click OK and exit from control Panel.

Step 9: Now run command prompt. Start -> cmd.

Step 10: Now compile your file using the command javac and provide the full path of the .java file.

Note: You might need to restart your computer if it does not work in the first go.
If even after this your javac command does not work then uninstall your JDK kit. Restart your computer and then reinstall the JDK kit and perform the above steps again.
If the problem still exists, then you need to change your JDK kit.

After successfully compiling your program you will see a *.class file on the same location as your  *.java file.

Now use the command "java" to execute your program:

eg: If the .class file after compiling is java1.class, then you use the command "java C:\ Users\Prakhar\Desktop\java1"

Happy to Help!!! Enjoy Coding!!!!

For any queries comment below...

This blog will try to cover all important JAVA APIs and tools which are necessary and most widely used in Competitive Programming.
If any corrections or suggestions you want to give please post in comments.
if(you==find_this_blog_useful){
       //   DO LIKE/ COMMENT/ SHARE;
          suggest.corrections;
}

Multiple Inputs in same line.

Multiple Inputs in same line.

This one is for beginners!!

Usually the input format in competitive programming questions is as follows:

2 3 2 1 2

1 2 3

4 5 6 1

. ..  so on

If you are new to competitive programming and JAVA(Newbie here too, as in you only have a basic knowledge of java and coded back in high school) is all you know how to code in, then this is an issue you may face. HOW TO TAKE MULTIPLE INPUTS IN SAME LINE IN JAVA!!! (we are avoiding Scanner class here because it is easily the most convenient way of reading in input, however it is very slow and not recommended unless the input is very small. ( less than 50KB of data is to be read ))

Well don't worry here is a solution. I will be discussing a couple of cases which you may face.  

Case 1: Method 1

              1 2 3 4 5

             

Java Code:

                

 Note: use BufferedInputStream for reading inputs in JAVA because it is considered as the fastest way of reading inputs. Scanner class

The following code will read five inputs in same line and print the same.

         import java.io.*;

     class inputMlines{

           public static void main(String[] args)throws IOException{

                             BufferedReader inp = new BufferedReader (new InputStreamReader(System.in));

               double[] j= new double[5];
            String[] s2 = inp.readLine().split(" ");
                j[0]=Double.parseDouble(s2[0]);
                j[1]=Double.parseDouble(s2[1]);

                                j[2]=Double.parseDouble(s2[2]);

                j[3]=Double.parseDouble(s2[3]);

                j[4]=Double.parseDouble(s2[4]); 

             for(int i=0;i<5;i++)

                  System.out.print(j[i]+" ");

            }//main function ends

        } // class closed

==================================================================

Case 2: Method 1

       1 2 3

       2 3 3

Java Code:

        the following code takes input in the above format and prints nothing.      

import java.io.*;

     class inputMlines{

           public static void main(String[] args)throws IOException{

                             BufferedReader inp = new BufferedReader (new InputStreamReader(System.in));

               double[] j= new double[3];

       for(int input=0;input<2;input++){
            String[] s2 = inp.readLine().split(" ");
                j[0]=Double.parseDouble(s2[0]);
                j[1]=Double.parseDouble(s2[1]);

                                j[2]=Double.parseDouble(s2[2]);

           }//for loop ends.               

            }//main function ends

        } // class closed

you can generalise this method after trying yourself.

==================================================================

That is all for this post. Please leave your QUERIES, SUGGESTIONS, BETTER METHODS OR any CORRECTIONS you think in the comments.

Have a nice day!!