we ask for user input in c by writing & (ampersand) but how to achieve this in java ?

[naved momin]

we ask for user input in c by writing & (ampersand) but how to achieve this in java ?
i mean how to take input from user ?

[N Sahni]

Here is the sample code for getting user input in Java through command-line:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Testing {
	public static void main(String[] args) {
		String value = null;
		//	Prompt user for any input.
		System.out.print("Enter Any Value: ");
		//	open standard input
	    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    // 	read the value from the command-line
	    try {
	    	value = br.readLine();
	    	System.out.println("Entered value is " + value);
	    } catch (IOException io) {
	    	System.out.println("IO error trying to read your value! " + io.getMessage());
	    }
	}
}

[Kammaganti Kamal]

naved momin wrote:we ask for user input in c by writing & (ampersand) but how to achieve this in java ?
i mean how to take input from user ?

Read about "System.in" in java .If not , then make further reading on this .. this will solve your question

[Campbell Ritchie]

naved momin wrote:we ask for user input in c by writing & (ampersand) . . .

No you don't. The & supplies an address for the data to be put into, from the scanf() procedure in C.

It is possible to use Readers, as you have already been shown, but it is much easier to use instances of the java.util.Scanner class.

[Campbell Ritchie]

N Sahni wrote:Here is the sample code for getting user input in Java through command-line: . . .

But you didn't close the Readers.

[Luigi Plinge]

It's a bit easier in Java 6:

import java.io.Console;

public class Hello {

    public static void main(String[] args) {
        Console cons = System.console();
        cons.writer().println("Enter your name");
        String name = cons.readLine();
        cons.writer().println("Hello " + name);
    }
}

[Luigi Plinge]

public class HaveAConversation {
    
    public static void main(String[] args) {
        pr("Enter your name");
        pr("Hello " + rd());
        pr("What's the weather like?");
        pr("Great, I like it when it's " + rd() + ".");
        pr("Do you know the meaning of life?");
        if(rd().equals("42")) pr("Correct! Your computer lives another day.");
        else pr("Wrong... deleting all your files!");
    }
    
    public static void pr(String s) { System.console().writer().println(s); }
    public static String rd() { return System.console().readLine(); }
}

[Rob Spoor]

Campbell Ritchie wrote:

N Sahni wrote:Here is the sample code for getting user input in Java through command-line: . . .

But you didn't close the Readers.

Which is a good thing in this case. Closing the Readers would close System.in which will cause it to become useless within the entire JVM until it exits.

[Luigi Plinge]

Just saw that readLine() can take a prompt. So this is N Sahni's example in Java 6.

public class Testing {
    public static void main(String[] args) {
        
        String value = System.console().readLine("Enter Any Value: ");
        System.out.println("Entered value is " + value);
    }
}

Of course, you could make it shorter by in-lining the expression for value, at a slight cost to readability.

[Campbell Ritchie]

Rob Spoor wrote:. . . Closing the Readers would close System.in which will cause it to become useless within the entire JVM until it exits.

I never knew that. Thank you.

Beware of Console; if you don't use the java tool to start your application, System.console() may return null, and you will suffer an Exception.