Sams Teach Yourself C in 21 Days

System.out.println(“This text will be displayed on the screen.”);

System.out.println(s); // Assumes s is a String object.

Text input is a bit more complicated. Although there is a System.inobject that can be

used for keyboard input, on its own it is suitable only for single characters. To input a

line of text, which is usually what you need to do, you must use a couple of higher-level

classes called BufferedReaderandInutStreamReader. Rather than trying to explain the

details, I’ll just tell you the required steps:

1. Import java.lang.System, java.io.InputStreamReader, and java.io.BufferedReader.


2. Declare a variable of type BufferedReader.


3. Initialize the variable created in step 2 as follows (assuming the variable is named
   kb):
   kb = new BufferedReader(new InputStreamReader(System.in));


4. Call the object’s readLinemethod to input a line of text from the keyboard.
   The sample program in Listing B4.2 shows how this is done.

LISTINGB4.2 InputOutputTest.java demonstrates console I/O

1: import java.lang.System;

2: import java.io.InputStreamReader;

3: import java.io.BufferedReader;

4: import java.io.IOException;

5:

6: public class InputOutputTest {

7:

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

9: // Set up to read lines from the keyboard.

10: BufferedReader kb;

11: String s1;

12:

13: kb = new BufferedReader(new InputStreamReader(System.in));

14: System.out.println(“Enter a line of text: “);

15: s1 = kb.readLine();

16: System.out.println(“You entered “ + s1);

17:

18: }

19: }

Enter a line of text: Java programming

You entered Java programming

Lines 1–4 of this program import the required Java classes. Line 6 defines the

classInputOutputTest, representing the test program. The throws IOException

714 Bonus Day 4

OUTPUT

ANALYSIS

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