Output

An output stream sends data to an output device.  The System class with methods for displaying output. For displaying data to the standard output stream, which are:

print() method

displays data and leaves the insertion point at the end of the output

println() 

moves the insertion point to the next line after displaying output. 

Example

public class MulticulturalGreeting {

     public static void main(String[] args) {

          System.out.print("Hello");

          System.out.print("Buenos Dias");

          System.out.println("Bonjour");

          System.out.println("How do you greet another?");

     }

}

Example Output

HelloBuenos DiasBonjour

How do you greet another?

Formatting Output

An escape sequence is a backslash (\) followed by a symbol that together represent a character. Escape sequences are used to display special characters.

          Common escape sequences include:

\n newline

\t tab (8 spaces)

\\ backslash

\" double quotation mark

Example

public static void main(String[] args) {

System.out.print("Hello\t");

System.out.print("Buenos Dias\t");

System.out.println("Bonjour");

System.out.println("How do you greet another?");

}

Example output

Hello         Buenos Dias         Bonjour

How do you greet another?

Input

Scanner methods for user input (Basics)

Scanner input = new Scanner(System.in);

input.next();       // input of a single word 

input.nextLine();   // input of multiple words

input.nextInt();     // input of an integer

input.nextDouble(); // decimal number input

When to use Scanner class methods

• • The next() method should be used for reading string data after numeric data has been read. 

  • If the nextLine() method is used, the end-of-line character left by the numeric entry is read and any text typed is ignored.

Example Code

System.out.print("Enter age: ");

age = input.nextInt();

System.out.print("Enter first name: ");

firstName = input.next();

System.out.println("Welcome, "+firstName+"! you are "+age+" years old.");

Example Output

Enter age: 12

Enter first name: John

Welcome, John! you are 12 years old.

• • Alternatively, a statement can be added to read the end-of-line character left by the numeric entry, so that the nextLine() method can be used to read a string that may contain white space:

Example Code

System.out.print("Enter age: ");

age = input.nextInt();

input.nextLine();           //removes end-of-line

System.out.print("Enter full name: ");

fullName = input.nextLine();

System.out.println("Hello, "+age+ " year-old "+fullName+"!");

Example Output

Enter age: 34

Enter full name: John Lewis

Hello, 34 year-old John Lewis!