1,
import javax.swing.JOptionPane; public class RandomInt { public static void main( String args[] ) { int value; String output = ""; for ( int i = 1; i <= 1000; i++ ) { value = 1 + (int) ( Math.random() * 6 ); output += value + " "; if ( i % 5 == 0 ) output += " "; } JOptionPane.showMessageDialog( null, output, "20 Random Numbers from 1 to 6", JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }

2,
public class MethodOverload {
public static void main(String[] args) {
System.out.println("The square of integer 7 is " + square(7));
System.out.println("
The square of double 7.5 is " + square(7.5));
}
public static int square(int x) {
return x * x;
}
public static double square(double y) {
return y * y;
}
}

方法重载
3,
System.out.println()
可以输出任意形式