java中byte、 int、char、long、float、double各占多少字节数

赋值规则：double>float>long>int>byte int>char boolean无法比较 string是类！！！

        intVariable=byteVariable;//int > byte
        // characterVariable=byteVariable;//err
        // byteVariable=characterVariable;//err ==>char与byte无法比较
        intVariable=characterVariable;//int>char
        longVariable=intVariable;//long>int
        floatVariable=longVariable;//float >long
        doubleVariable=floatVariable;//double > float
        // str=charVariable;//str与char无法比较
        str= String.valueOf(doubleVariable);