Java——Java杂谈

 1 import java.util.Random;
 2 
 3 public class ForEachFloat {
 4     public static void main(String[] args) {
 5         Random rand = new Random(47);
 6         float f[] = new float[10];
 7         for(int i = 0; i < 10; i++) {
 8             f[i] = rand.nextFloat();
 9         }
10         for(float x : f) {
11             System.out.println(x);
12         }
13     }
14 }

 1 public class Flower {
 2     int petalCount = 0;
 3     String s = "initial value";
 4     
 5     Flower(int perals) {
 6         petalCount = perals;
 7         System.out.println("Constructor w/ int arg only, petalCount= " + petalCount);
 8     }
 9 
10     Flower(String ss) {
11         System.out.println("Constructor w/ int arg only, s= " + ss);
12         s = ss;
13     }
14 
15     Flower(String s, int petals) {
16         this(petals);
17 //!　　  this(s); //不能调用两个！
18         this.s = s;
19         System.out.println("String & int args");
20     }
21 
22     Flower(){
23         this("hi", 45);
24         System.out.println("default constructor (no args)");
25     }
26 
27     void printPetalCount() {
28 //!　　  this(11); //不能在构造器之外的任何方法中调用构造器
29         System.out.println("petalCount = " + petalCount + " s = " + s);
30     }
31 
32     public static void main(String[] args) {
33         Flower x = new Flower();
34         x.printPetalCount();
35     }
36 }