Java.io.Console.readLine() Method

Description

The java.io.Console.readLine(String fmt, Object... args) method provides a formatted prompt, then reads a single line of text from the console.

Declaration

Following is the declaration for java.io.Console.readLine(String fmt, Object... args) method:

public String readLine(String fmt, Object... args)

Parameters

• fmt

• args

Return Value

This method returns the string containing the line read from the console, not including any line-termination characters or null if an end of the stream has been reached.

Exception

• IllegalFormatException -- If a format string contains an illegal syntax, a format specifier that is incompatible with the given arguments, insufficient arguments given the format string, or other illegal conditions.

• IOError -- if an I/O error occurs.

Example

The following example shows the usage of java.io.Console.readLine(String fmt, Object... args) method.

package com.tutorialspoint;

import java.io.Console;

public class ConsoleDemo {
   public static void main(String[] args) {
      
      Console cnsl = null;
      String fmt = "%1$4s %2$5s %3$10s%n";
      String alpha = null;
      
      try{
         // creates a console object
         cnsl = System.console();

         // if console is not null
         if (cnsl != null) {
            
            // read line from the user input
            alpha = cnsl.readLine(fmt, "Enter","Alphabets: ");
            
            // prints
            System.out.println("Alphabets entered: " + alpha);
         }      
      }catch(Exception ex){
         
         // if any error occurs
         ex.printStackTrace();      
      }
   }
}

Let us compile and run the above program, this will produce the following result:

Enter Alphabets: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Alphabets entered : ABCDEFGHIJKLMNOPQRSTUVWXYZ