/基本类型:浮点型(float)float score = 95.5;//基本类型:双浮点型(double)double pai = 3.14159;//基本类型:无类型(void),你看我的main方法叫...也或许是为了兼容c,为了更贴合硬件。...:signed , unsigned , short , long signed代表有符号,二进制最左边需要一个位来表示正负,这意味着可表示的数会少 unsigned代表无符号,二进制位中不需要有表示正负的位...32767long int8 个字节-9,223,372,036,854,775,808 到 9,223,372,036,854,775,807signed long int8 个字节-9,223,372,036,854,775,808...到 9,223,372,036,854,775,807unsigned long int8 个字节0 到 18,446,744,073,709,551,615float4 个字节精度型占4个字节(32