Create a class with a String field that is initialized at the point of definition, and another one that is initialized by the constructor. What is the difference between the two approaches.
1 class Test{ 2 String s1; 3 String s2="hello world"; 4 String s3; 5 Test(){ 6 s3="hello java"; 7 } 8 } 9 public class ConstructorTest { 10 11 public static void main(String[]args){ 12 13 Test t=new Test(); 14 System.out.println(t.s1); 15 System.out.println(t.s2); 16 System.out.println(t.s3); 17 18 } 19 }
输出
null hello world hello java
Java:thinging in java p158 exercise 1
原文：http://www.cnblogs.com/taoxiuxia/p/4438783.html