Java examples for File Path IO:Scanner
Standard Console Output
/****************************************************************************** * Copyright 2002-2015, Robert Sedgewick and Kevin Wayne. * * This file is part of algs4.jar, which accompanies the textbook * * Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne, * Addison-Wesley Professional, 2011, ISBN 0-321-57351-X. * http://algs4.cs.princeton.edu/* www . j av a 2s . c o m*/ * * * algs4.jar is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * algs4.jar is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with algs4.jar. If not, see http://www.gnu.org/licenses. ******************************************************************************/ /****************************************************************************** * Compilation: javac StdOut.java * Execution: java StdOut * Dependencies: none * * Writes data of various types to standard output. * ******************************************************************************/ package edu.pucit.cs.algo; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.io.UnsupportedEncodingException; import java.util.Locale; /** * This class provides methods for printing strings and numbers to standard output. * <p> * <b>Getting started.</b> * To use this class, you must have <tt>StdOut.class</tt> in your * Java classpath. If you used our autoinstaller, you should be all set. * Otherwise, download * <a href = "http://introcs.cs.princeton.edu/java/stdlib/StdOut.java">StdOut.java</a> * and put a copy in your working directory. * <p> * Here is an example program that uses <code>StdOut</code>: * <pre> * public class TestStdOut { * public static void main(String[] args) { * int a = 17; * int b = 23; * int sum = a + b; * StdOut.println("Hello, World"); * StdOut.printf("%d + %d = %d\n", a, b, sum); * } * } * </pre> * <p> * <b>Differences with System.out.</b> * The behavior of <code>StdOut</code> is similar to that of {@link System#out}, * but there are a few subtle differences: * <ul> * <li> <code>StdOut</code> coerces the character-set encoding to UTF-8, * which is a standard character encoding for Unicode. * <li> <code>StdOut</code> coerces the locale to {@link Locale#US}, * for consistency with {@link StdIn}, {@link Double#parseDouble(String)}, * and floating-point literals. * <li> <code>StdOut</code> <em>flushes</em> standard output after each call to * <code>print()</code> so that text will appear immediately in the terminal. * </ul> * <p> * <b>Reference.</b> * For additional documentation, * see <a href="http://introcs.cs.princeton.edu/15inout">Section 1.5</a> of * <em>Introduction to Programming in Java: An Interdisciplinary Approach</em> * by Robert Sedgewick and Kevin Wayne. * * @author Robert Sedgewick * @author Kevin Wayne */ public final class StdOut { // force Unicode UTF-8 encoding; otherwise it's system dependent private static final String CHARSET_NAME = "UTF-8"; // assume language = English, country = US for consistency with StdIn private static final Locale LOCALE = Locale.US; // send output here private static PrintWriter out; // this is called before invoking any methods static { try { out = new PrintWriter(new OutputStreamWriter(System.out, CHARSET_NAME), true); } catch (UnsupportedEncodingException e) { System.out.println(e); } } // don't instantiate private StdOut() { } /** * Closes standard output. */ public static void close() { out.close(); } /** * Terminates the current line by printing the line-separator string. */ public static void println() { out.println(); } /** * Prints an object to this output stream and then terminates the line. * * @param x the object to print */ public static void println(Object x) { out.println(x); } /** * Prints a boolean to standard output and then terminates the line. * * @param x the boolean to print */ public static void println(boolean x) { out.println(x); } /** * Prints a character to standard output and then terminates the line. * * @param x the character to print */ public static void println(char x) { out.println(x); } /** * Prints a double to standard output and then terminates the line. * * @param x the double to print */ public static void println(double x) { out.println(x); } /** * Prints an integer to standard output and then terminates the line. * * @param x the integer to print */ public static void println(float x) { out.println(x); } /** * Prints an integer to standard output and then terminates the line. * * @param x the integer to print */ public static void println(int x) { out.println(x); } /** * Prints a long to standard output and then terminates the line. * * @param x the long to print */ public static void println(long x) { out.println(x); } /** * Prints a short integer to standard output and then terminates the line. * * @param x the short to print */ public static void println(short x) { out.println(x); } /** * Prints a byte to standard output and then terminates the line. * <p> * To write binary data, see {@link BinaryStdOut}. * * @param x the byte to print */ public static void println(byte x) { out.println(x); } /** * Flushes standard output. */ public static void print() { out.flush(); } /** * Prints an object to standard output and flushes standard output. * * @param x the object to print */ public static void print(Object x) { out.print(x); out.flush(); } /** * Prints a boolean to standard output and flushes standard output. * * @param x the boolean to print */ public static void print(boolean x) { out.print(x); out.flush(); } /** * Prints a character to standard output and flushes standard output. * * @param x the character to print */ public static void print(char x) { out.print(x); out.flush(); } /** * Prints a double to standard output and flushes standard output. * * @param x the double to print */ public static void print(double x) { out.print(x); out.flush(); } /** * Prints a float to standard output and flushes standard output. * * @param x the float to print */ public static void print(float x) { out.print(x); out.flush(); } /** * Prints an integer to standard output and flushes standard output. * * @param x the integer to print */ public static void print(int x) { out.print(x); out.flush(); } /** * Prints a long integer to standard output and flushes standard output. * * @param x the long integer to print */ public static void print(long x) { out.print(x); out.flush(); } /** * Prints a short integer to standard output and flushes standard output. * * @param x the short integer to print */ public static void print(short x) { out.print(x); out.flush(); } /** * Prints a byte to standard output and flushes standard output. * * @param x the byte to print */ public static void print(byte x) { out.print(x); out.flush(); } /** * Prints a formatted string to standard output, using the specified format * string and arguments, and then flushes standard output. * * * @param format the <a href = "http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax">format string</a> * @param args the arguments accompanying the format string */ public static void printf(String format, Object... args) { out.printf(LOCALE, format, args); out.flush(); } /** * Prints a formatted string to standard output, using the locale and * the specified format string and arguments; then flushes standard output. * * @param locale the locale * @param format the <a href = "http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax">format string</a> * @param args the arguments accompanying the format string */ public static void printf(Locale locale, String format, Object... args) { out.printf(locale, format, args); out.flush(); } /** * Unit tests some of the methods in <tt>StdOut</tt>. */ public static void main(String[] args) { // write to stdout StdOut.println("Test"); StdOut.println(17); StdOut.println(true); StdOut.printf("%.6f\n", 1.0 / 7.0); } }