第 1 章 画面 文字 表示 Java Java Java Java Java JRE Java JDK
21 1-1 Java Java Java Java 誕生 Fig.1-1 Oak Java Sun Microsystems 2010 Oracle Java Oracle 4 Java http://www.java.com/ http://www.alice.org/ Fig.1-1Java Alice
3 Java 特徴 Java 1-1 Write Once, Run Anywhere. Column 1-3 C++
41 Java Java Java 発展 Table 1-1 1.2 1.5 Java 2 1.6 Java 5.0 1.5 6.1 7.3 EoD Ease of Development Java Standard EditionSE Enterprise EditionEE Micro EditionME
5 Table 1-1Java JDK 1.0 1996 / 1 JDK 1.1 1997 / 2 J2SE 1.2 Playground 1998 / 12 J2SE 1.3 Kestrel 2000 / 5 J2SE 1.4.0 Merlin 2002 / 2 J2SE 5.0 1.5 Tiger 2004 / 9 Java 1-1 Java SE 6 1.6 Mustang 2006 / 12 Java SE 7 1.7 Dolphin 2011 / 7 Java SE 8 1.8 2014 / 3 学習 準備 Java JDKJava Development Kit Java SDKSoftware Development Kit Java C C++
61 1-2 画面 文字 表示 作成 実行 List 1-1 Java // class Hello { List 1-1 System.out.println("Java"); System.out.println(""); Chap01/Hello.java 実行結果 Java " { [ ] ( ) " /. ; Table 1-2p.17 source program source file source class class Hello.java Hello.java
7 Fig.1-2 MeikaiJava Chap01, Chap02, p.5 1-2 MeikaiJava Chap1 Hello.java HowAreYou1.java HowAreYou4.java Chap2 Chap3 8 11 Fig.1-2 Fig.1-3 List 1-1 // class Hello { System.out.println("Java"); System.out.println("");.java / Chap01/Hello.java 実行結果 Java Fig.1-3
81 実行 Fig.1-4 a bytecode b class Hello { // a javac b java Hello.java Hello.class Fig.1-4 a compile Hello.java Column 1-1 javac Hello.java Ÿ.java UNIX % MS-Windows C:\> C: > Fig.1-5 Hello.class class file MeikaiJava Chap1 Hello.java Hello.class Hello.java Fig.1-5
9 b Hello java Hello Ÿ.class p.6 List 1-1 1-2 javac java Column 1-1 Linux MS-Windows OS Java cd cd /MeikaiJava/Chap01 Ÿ MS-Windows MeikaiJava D d: Ÿ OS /, \, /
101 ( 注釈 ) // // comment 4 4 4 4 a traditional comment /* */ /* */ /* */ */ /* b b documentation comment /** */ a 13 /** */
11c end of line comment // // /** /*!! */ */ */ */ // /* //!! */ // /*!! */ 1-2 Column 1-2 Java class Hello { // System.out.println("Java"); System.out.println(""); 実行結果 // // /* */ class Hello { /* System.out.println("Java"); System.out.println(""); */ 実行結果 4 4 4 4 4 4 4 4 4 4
121 構造 Fig.1-6 Hello main class Hello { System.out.println("Java"); System.out.println(""); Fig.1-6 宣言 Hello classclass declaration class { // main Hello Abc abc.java main main main method public static void (String[] args) // main
13文 main statement 4 4 Fig.1-7 main System.out.println("Java"); System.out.println(""); Fig.1-7 main main 1-2 Java main 7 if while main ; ; 4 4 4 4 4 Java main { 4 4 4 4 4 { 1-1 ;
141 文字列 System.out.println("Java"); System.out.println(""); "Java" "" " string literal "ABC" A B C Fig.1-8 15 "" "ABC" "Java" A B C J a v a 3 14 Fig.1-8 画面 出力 stream Fig.1-9 S ystem.o ut standard output stream println ( ) "ABC" " " Java
15println ln line println ln p rint List 1-2 System.out.println("ABC"); ABC Fig.1-9 HowAreYou1.java 1-2 List 1-2 // class HowAreYou1 { Chap01/HowAreYou1.java 実行結果 System.out.print(""); System.out.println(""); print println method main ( ) 7 System.out.print(...) System.out.println(...). 8 println ( ) System.out.println(); // ABC ABC ABC ABC
161 文字列 連結 + List 1-3 List 1-3 Chap01/HowAreYou2.java // class HowAreYou2 { 実行結果 System.out.println("" + ""); + System.out.println("" + ""); 改行 \n List 1-4 List 1-4 // class HowAreYou3 { System.out.println("\n"); Chap01/HowAreYou3.java 実行結果 \n 4 4 4 \ n \n \ 5-3
17記号文字 読 方 Table 1-2 MS-Windows \ List 1-4 Table 1-2 + - * / \ JIS $ %., : ; ' " ( ) { [ ] < >?! & ~ JIS - - ^ # _ System.out.println(" n"); =!! 1-2
181 自由形式記述 List 1-5 List 1-4 List 1-5 */class HowAreYou4 { public static void main( String [ ] args) { System. out. println ( "\n" ) ; /* Chap01/HowAreYou4.java 実行結果 free formatted classpublicvoidsystem, out, //, /* Sys tem " " System.out.println("\n ");
19JDKJava Java Java JREJava Java Runtime Environment Fig.1C-1 JRE JVMJava Java Virtual Machine JDK JDK JRE JRE Java JVM JRE Fig.1C-1JDK JRE JDK JRE MS-Windows Mac OS-X Linux Fig.1C-2 javac JVM Write Once, Run Anywhere. p.3 1-2 Column 1-3 JRE(Java 実行環境 ) JVM(Java 仮想 ) JVM JVM MS-Windows JRE JVM Mac OS-X JRE JVM Linux JRE MS-Windows Mac OS-X Linux Fig.1C-2Java JVM Java Java
201 List 1-1 List 1-4 main { Fig.1-10, 3, 6, 9, for (int i = 1; i <= 9; i++) { for (int j = 1; j <= 9; j++) { System.out.printf("%3d", i * j); System.out.println(); 4 p.134 Fig.1-10 1-2 1-3 1
21 C C++ Java 8 Java C++ puts printf Java System.out.print 1-2 Column 1-4 文字 1 MS-Windows Fig.1-10 8 Fig.1C-3 for (int i = 1; i <= 9; i++) { for (int j = 1; j <= 9; j++) { System.out.printf("%3d", i * j); System.out.println(); Fig.1C-3Fig.1-10 8
221 Java Java Java JDK.java javac.class java main main System.out.print System.out.println " " + \n
23.java Abc.java // /* */ /** */ // Chap01/Abc.java Abc 1 class Abc { main System.out.print("ABC"); System.out.print("DEF" + "GHI"); System.out.println("JKL\nXYZ"); System.out.print(...) // System.out.println(...) // javac Abc.javaŸ 4 4 4 4.java Abc.class.class java AbcŸ 実行結果 ABCDEFGHIJKL XYZ 4 4 4 4.class p.7