Map的toString()方法问题
import java.util.HashMap;
public class Test {
public static void main(String[] args) {
HashMap map=new HashMap();
map.put("key1", "value1");
map.put("key2", "value2");
map.put("key3", "value3");
System.out.println(map.toString());
}
}
如上一点程序,输出为:
{key1=value1, key3=value3, key2=value2}
为什么不是 {key1=value1, key2=value2, key3=value3}
求解答!