将实例变量初始化为null，“"或0 [英] Initialising instance variables as null, "" or 0
问题描述
使用默认值初始化变量时：
When initialising variables with default values:
有什么区别：
private static String thing = null;
和
private static String thing = "";
我不明白哪个更好，为什么以及处理其他数据的最佳方式是什么类型。
I'm not understanding which is better and why nor what is the best way to deal with other data types.
private static int number = 0;
private static double number = 0;
private static char thing = 0;
抱歉，我很难学习新语言。
推荐答案
除了将 String 初始化为空字符串
Except for initializing String to an empty string
private static String thing = "";
其他分配是不必要的：Java会将原始类型的所有成员变量设置为默认值，并且所有引用类型（包括 java.String ）到 null 。
the other assignments are unnecessary: Java will set all member variables of primitive types to their default values, and all reference types (including java.String) to null.
将 String 初始化为 null 或空字符串的决定取决于您：有nothing和empty string * 之间的区别，所以你必须决定你想要哪一个。
* 无和空字符串之间的差异源于观察到
null <无法进行任何操作/ code> string - 例如，它的长度未定义，您无法迭代其字符。相反，空字符串的长度是明确定义的（零），您可以迭代它的字符（它是一个空的迭代）。
The decision to initialize a String to a null or to an empty string is up to you: there is a difference between "nothing" and "empty string" *, so you have to decide which one you want.
* The differences between "nothing" and "empty string" stem from the observation that no operations are possible on a null string - for example, its length is undefined, and you cannot iterate over its characters. In contrast, the length of an empty string is well-defined (zero), and you can iterate over its characters (it's an empty iteration).
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