Java 定义变量"空"与"NULL"
2011-07-30 09:25
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String s;
System.out.println(s);
在Eclipse里面就会报错,是因为你没有初始化s.
String s = null;
System.out.println(s);
这样就不会报错.
空变量是没有值的,NULL是有值的.在对"对象或变量"的调用前进行一个初始化是符合JAVA编程规范的,它是一个良好的编程习惯.
System.out.println(s);
在Eclipse里面就会报错,是因为你没有初始化s.
String s = null;
System.out.println(s);
这样就不会报错.
空变量是没有值的,NULL是有值的.在对"对象或变量"的调用前进行一个初始化是符合JAVA编程规范的,它是一个良好的编程习惯.
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