C++学习——int、long、long long, double, long double等的占用空间及取值范围

unsigned int 0~4294967295

int 2147483648~2147483647
unsigned long 0~4294967295
long 2147483648~2147483647
long long的最大值:9223372036854775807
long long的最小值:-9223372036854775808
unsigned long long的最大值:1844674407370955161

__int64的最大值:9223372036854775807
__int64的最小值:-9223372036854775808
unsigned __int64的最大值:18446744073709551615

#include<iostream>  
#include<string>  
#include <limits>  
using namespace std;  
  
int main()  
{  
    cout << "type: \t\t" << "************size**************"<< endl;  
    cout << "bool: \t\t" << "所占字节数:" << sizeof(bool);  
    cout << "\t最大值:" << (numeric_limits<bool>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<bool>::min)() << endl;  
    cout << "char: \t\t" << "所占字节数:" << sizeof(char);  
    cout << "\t最大值:" << (numeric_limits<char>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<char>::min)() << endl;  
    cout << "signed char: \t" << "所占字节数:" << sizeof(signed char);  
    cout << "\t最大值:" << (numeric_limits<signed char>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<signed char>::min)() << endl;  
    cout << "unsigned char: \t" << "所占字节数:" << sizeof(unsigned char);  
    cout << "\t最大值:" << (numeric_limits<unsigned char>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<unsigned char>::min)() << endl;  
    cout << "wchar_t: \t" << "所占字节数:" << sizeof(wchar_t);  
    cout << "\t最大值:" << (numeric_limits<wchar_t>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<wchar_t>::min)() << endl;  
    cout << "short: \t\t" << "所占字节数:" << sizeof(short);  
    cout << "\t最大值:" << (numeric_limits<short>::max)();  
    cout << "\t\t最小值:" << (numeric_limits<short>::min)() << endl;  
    cout << "int: \t\t" << "所占字节数:" << sizeof(int);  
    cout << "\t最大值:" << (numeric_limits<int>::max)();  
    cout << "\t最小值:" << (numeric_limits<int>::min)() << endl;  
    cout << "unsigned: \t" << "所占字节数:" << sizeof(unsigned);  
    cout << "\t最大值:" << (numeric_limits<unsigned>::max)();  
    cout << "\t最小值:" << (numeric_limits<unsigned>::min)() << endl;  
    cout << "long: \t\t" << "所占字节数:" << sizeof(long);  
    cout << "\t最大值:" << (numeric_limits<long>::max)();  
    cout << "\t最小值:" << (numeric_limits<long>::min)() << endl;  
    cout << "unsigned long: \t" << "所占字节数:" << sizeof(unsigned long);  
    cout << "\t最大值:" << (numeric_limits<unsigned long>::max)();  
    cout << "\t最小值:" << (numeric_limits<unsigned long>::min)() << endl;  
    cout << "double: \t" << "所占字节数:" << sizeof(double);  
    cout << "\t最大值:" << (numeric_limits<double>::max)();  
    cout << "\t最小值:" << (numeric_limits<double>::min)() << endl;  
    cout << "long double: \t" << "所占字节数:" << sizeof(long double);  
    cout << "\t最大值:" << (numeric_limits<long double>::max)();  
    cout << "\t最小值:" << (numeric_limits<long double>::min)() << endl;  
    cout << "float: \t\t" << "所占字节数:" << sizeof(float);  
    cout << "\t最大值:" << (numeric_limits<float>::max)();  
    cout << "\t最小值:" << (numeric_limits<float>::min)() << endl;  
    cout << "size_t: \t" << "所占字节数:" << sizeof(size_t);  
    cout << "\t最大值:" << (numeric_limits<size_t>::max)();  
    cout << "\t最小值:" << (numeric_limits<size_t>::min)() << endl;  
    cout << "string: \t" << "所占字节数:" << sizeof(string) << endl;  
    // << "\t最大值:" << (numeric_limits<string>::max)() << "\t最小值:" << (numeric_limits<string>::min)() << endl;  
    cout << "type: \t\t" << "************size**************"<< endl;  
    return 0;  
}

输出结果为:
在这里插入图片描述

注意:

一字节表示八位,即:1byte = 8 bit;

int: 4byte = 32 bit 有符号signed范围:2^31-1 ~ -2^31即:2147483647 ~ -2147483648无符号unsigned范围:2^32-1 ~ 0即:4294967295 ~ 0

long: 4 byte = 32 bit 同int型

double: 8 byte = 64 bit 范围:1.79769e+308 ~ 2.22507e-308

long double: 12 byte = 96 bit 范围: 1.18973e+4932 ~ 3.3621e-4932

float: 4 byte = 32 bit 范围: 3.40282e+038 ~ 1.17549e-038

int、unsigned、long、unsigned long 、double的数量级最大都只能表示为10亿,即它们表示十进制的位数不超过10个,即可以保存所有9位整数。而short只是能表示5位;

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转载自blog.csdn.net/weixin_45525272/article/details/105015073