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1个字节(byte)是8bit.
我采用的是64位系统,64位指CPU寄存器的数据宽度是64位的。
short 和 int:short比int更节省空间,short占内存是Int的一半,当要//代码效果参考:https://v.youku.com/v_show/id_XNjQwNjg3MjkwOA==.html
考虑程序的空间性而且short足以存储所需数据的话就用short。float 和 double:double精度高,有效数字16位,float精度7位。但double消耗内存是float的两倍,double的运算速度比float慢得 多,能用单精度时不要用双精度(以省内存,加快运算速度)
64位系统:
int型:4字节
char型:1字节
bool型:1字节
double型:8字节
float型:4字节
long型:8字节
short型:2字节
unsigned int型:4字节
unsigned long型:8字节
bool型:1字节
测试程序:
//============================================================================
// Name : 各类型大小.cpp
// Author :
// Version :
// Copyright : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================
#include
using namespace std;
int main() {
cout[""int型:""[sizeof(int)[""字节""[endl;
cout[""char型:""[sizeof(char)[""字节""[endl;
cout[""bool型:""[sizeof(bool)[""字节""[endl;
cout[""double型:""[sizeof(double)[""字节""[endl;
cout[""float型:""[sizeof(float)[""字节""[endl;
//代码效果参考:https://v.youku.com/v_show/id_XNjQwNjg2MzQ2OA==.html
cout[""long型:""[sizeof(long)[""字节""[endl;cout[""short型:""[sizeof(short)[""字节""[endl;
cout[""unsigned int型:""[sizeof(unsigned int)[""字节""[endl;
cout[""unsigned long型:""[sizeof(unsigned long)[""字节""[endl;
cout[""bool型:""[sizeof(bool)[""字节""[endl;
return 0;
}
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