关于java:当一个值被赋值为null引起的javalangNullPointerException

上代码

String ss = null;// falseSystem.out.println(ss == "");// 报错 java.lang.NullPointerException// System.out.println(ss.equals(""));// falseSystem.out.println(Objects.equals(ss,""));Long id = null;System.out.println(id);// 报错System.out.println(id == 0);// falseSystem.out.println(Objects.equals(id,0));// trueSystem.out.println(Objects.equals(id,null));

总结

当前是不是用到比拟的时候,都须要用objects.equals??