Java input and output statements

1. Enter the sentence

In Java, input depends on the Scanner class . Scanner is a new class added in JDK 1.5. You can use this class to create an object:

 Scannerreader=newScanner(System.in);

The reader object calls the following methods to read various basic types of data entered by the user on the command line:

nextBoolean(): input Boolean value

nextByte(): input bytes

nextShort(): input short integer

nextInt(): input integer

nextLong(): input long integer

nextFloat(): input single-precision floating point number

nextDouble(): input double precision floating point number

2. Output statement

There are three commonly used output statements in Java:

1) System.out.println();

Line wrap printing will automatically wrap after output.

2) System.out.print();

Print without line breaks.

3) System.out.printf();

Output according to the format.

Common format control characters are as follows:

Notice :

When using System.out.println() or System.out.print() to output a string constant, "carriage return" cannot appear, for example:

 System.out.println("Hello, nice to meet you");//This way of writing cannot be compiled.

If we need to output a longer string, we can break the string into several parts and then use the concatenation symbol + to connect them end to end, for example:

 System.out.println("Hello," + "Nice to meet you");//This is the correct way of writing