/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}System的一个成员,用以处理标准输出
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/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}在屏幕上显示一行信息
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/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}实际参数,显示一个字符串
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/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}程序块的开始和结束
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/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}分号表示语句结束
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/*本程序实现一个应用,将“HelloWorld!”显示*/publicclassHelloWorld{publicstaticvoidmain(String[]args){//Display"Hellojava!"System.out.println("Hellojava!");}}公共的,而非私有的。
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JAVA语言开发环境
JAVA开发工具(JavaDevelopmentKit,JDK),1.2版本J2SDKJAVA平台的三个版本
J2SE:Java2标准版J2EE:Java2的企业版J2ME:Java2微型版
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JAVA语言开发环境
建立环境
安装jdk安装集成开发环境
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JAVA小程序(Applet)
importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}
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importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}告诉编译器程序所要用的类
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importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}表示这里定义的Hello类是一种JApplet类
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importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}浏览器调用paint方法,进行绘制
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importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}Graphics类的对象g对应于显示区域
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importjavax.swing.*;importjava.awt.*;publicclassHelloextendsJApplet{publicvoidpaint(Graphicsg){g.drawString("Helloworld",10,10);}}
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