头文件"limits"学习

#include<limits>
#include<iostream>
using namespace std; 
int main()
{
	cout<<"变量类型--------写法----------------对应值(无符号型是有符号性的二倍关系)"<<endl<<endl<<"最大值"<<endl; 
	cout<<"long long    ->LONG_LONG_MAX ="<<LONG_LONG_MAX<<endl;
	cout<<"short char   ->SCHAR_MAX     ="<<SCHAR_MAX<<endl;
	cout<<"short int    ->SHRT_MAX      ="<<SHRT_MAX<<endl;
	cout<<"int          ->INT_MAX       ="<<INT_MAX<<endl;
	cout<<"long int     ->LONG_MAX      ="<<LONG_MAX<<endl;
	cout<<"double       ->__DBL_MAX__   ="<<__DBL_MAX__<<endl;
	cout<<"float        ->__FLT_MAX__   ="<<__FLT_MAX__<<endl;
	cout<<"long double  ->__LDBL_MAX__  ="<<__LDBL_MAX__<<endl;
	
	cout<<endl<<"最小值"<<endl; 
	cout<<"long long    ->LONG_LONG_MIN ="<<LONG_LONG_MIN<<endl;
	cout<<"short char   ->SCHAR_MIN     ="<<SCHAR_MIN<<endl;
	cout<<"short int    ->SHRT_MIN      ="<<SHRT_MIN<<endl;
	cout<<"int          ->INT_MIN       ="<<INT_MIN<<endl;
	cout<<"long int     ->LONG_MIN      ="<<LONG_MIN<<endl;
	cout<<"double       ->__DBL_MIN__   ="<<__DBL_MIN__<<endl;
	cout<<"float        ->__FLT_MIN__   ="<<__FLT_MIN__<<endl;
	cout<<"long double  ->__LDBL_MIN__  ="<<__LDBL_MIN__<<endl;
	return 0;
 } 

运行结果：

网上看到 u010944926 博客中这样写。学习到一种numeric_limits的基本用法，

#include <limits>  
#include <iostream>  
using namespace std;  
  
int main() {  
    cout << boolalpha;  
  
    cout << "max(short): " << numeric_limits<short>::max() << endl;  
    cout << "min(short): " << numeric_limits<short>::min() << endl;  
  
    cout << "max(int): " << numeric_limits<int>::max() << endl;  
    cout << "min(int): " << numeric_limits<int>::min() << endl;  
  
    cout << "max(long): " << numeric_limits<long>::max() << endl;  
    cout << "min(long): " << numeric_limits<long>::min() << endl;  
  
    cout << endl;  
  
    cout << "max(float): " << numeric_limits<float>::max() << endl;  
    cout << "min(float): " << numeric_limits<float>::min() << endl;  
  
    cout << "max(double): " << numeric_limits<double>::max() << endl;  
    cout << "min(double): " << numeric_limits<double>::min() << endl;  
  
    cout << "max(long double): " << numeric_limits<long double>::max() << endl;  
    cout << "min(long double): " << numeric_limits<long double>::min() << endl;  
  
    cout << endl;  
  
    cout << "is_signed(char): "  
        << numeric_limits<char>::is_signed << endl;  
    cout << "is_specialized(string): "   
        << numeric_limits<string>::is_specialized << endl;  
}  

结果：