JavaSe 八种数据类型的默认值

                                                         占得字节                表示范围

byte    0                                                 1                          -128~127

int      0                                                 4                            -2的31次方 ~  2的31次方-1

short    0                                                2                              -2的15次方 ~  2的15次方-1

long    0                                                8                            -2的63次方 ~  2的63次方-1

char    '/u0000'  也就是空字符         

float   0.0f                                           4

double  0.0d                                       8

boolean   false