byte、short、int、long 的默认是都是 0。
boolean 默认值是 false。
char 的默认值是 ' '。
float、double 的默认是 0.0。
对象类型的默认值是 null。
public class Demo { private byte defByte; private short defShort; private int defInt; private long defLong; private float defFloat; private double defDouble; private char defChar; private boolean defBoolean; private Object defObject; public Demo() { System.out.print("byte="); System.out.println(defByte); System.out.print("short="); System.out.println(defShort); System.out.print("int="); System.out.println(defInt); System.out.print("long="); System.out.println(defLong); System.out.print("float="); System.out.println(defFloat); System.out.print("double="); System.out.println(defDouble); System.out.print("char=|"); System.out.print(defChar); System.out.println("| " + (int)(defChar)); System.out.print("boolean="); System.out.println(defBoolean); System.out.print("Object="); System.out.println(defObject); } public static void main(String[] args) { new Demo(); } }
输出结果:
byte=0 short=0 int=0 long=0 float=0.0 double=0.0 char=| | 0 boolean=false Object=null