在某些情况下，我们需要在不同的问题中使用特定数据类型的最小值或最大值。很难记住这种值。因此，C ++有一些宏，用于表示某些数据类型的最小和最大范围。其中一些没有宏，因为它们是无符号的，因此最小值将为0。
| 数据类型 | 范围 | 最小值的宏 | 最大值的宏 |
|---|---|---|---|
| char | -128至+127 | CHAR_MIN | CHAR_MAX |
| short char | -128至+127 | SCHAR_MIN | SCHAR_MAX |
| unsigned char | 0至255 | ----- | UCHAR_MAX |
| short int | -32768至+32767 | SHRT_MIN | SHRT_MAX |
| unsigned short int | 0至65535 | ----- | USHRT_MAX |
| int | -2147483648至+2147483647 | INT_MIN | INT_MAX |
| unsigned int | 0至4294967295 | ----- | INT_MAX |
| long int | -2147483648至+2147483647 | LONG_MIN | LONG_MAX |
| unsigned long int | 0至18446744073709551615 | ----- | ULONG_MAX |
| long long int | -9223372036854775808至+9223372036854775807 | LLONG_MIN | LLONG_MAX |
| unsigned long long int | 0至18446744073709551615 | ----- | ULLONG_MAX |
| float | 1.17549e-38至3.40282e + 38 | FLT_MIN | FLT_MAX |
float(negative) | -1.17549e-38至-3.40282e + 38 | -FLT_MIN | -FLT_MAX |
| double | 2.22507e-308至1.79769e + 308 | DBL_MIN | DBL_MAX |
double(negative) | -2.22507e-308至-1.79769e + 308 | -DBL_MIN | -DBL_MAX |
我们可以看到一个简单的程序来打印某些C ++数据类型的范围。
#include<iostream>
#include<limits.h> // for int,char macros
#include<float.h> // for float,double macros
using namespace std;
int main() {
cout << "char Range: (" << CHAR_MIN <<", " <<CHAR_MAX << ")\n";
cout << "short char Range: (" << SCHAR_MIN <<", " <<SCHAR_MAX << ")\n";
cout << "unsigned char Range: (" << 0 <<", " <<UCHAR_MAX << ")\n";
cout << "short int Range: (" << SHRT_MIN <<", " <<SHRT_MAX << ")\n";
cout << "unsigned short int Range: (" << 0 <<", " <<USHRT_MAX << ")\n";
cout << "int Range: (" << INT_MIN <<", " <<INT_MAX << ")\n";
cout << "unsigned int Range: (" << 0 <<", " <<UINT_MAX << ")\n";
cout << "long int Range: (" << LONG_MIN <<", " <<LONG_MAX << ")\n";
cout << "unsigned long int Range: (" << 0 <<", " <<ULONG_MAX << ")\n";
cout << "long long int Range: (" << LLONG_MIN <<", " <<LLONG_MAX << ")\n";
cout << "unsigned long long int Range: (" << 0 <<", " <<ULLONG_MAX << ")\n";
cout << "float Range: (" << FLT_MIN <<", " <<FLT_MAX << ")\n";
cout << "float(negative) Range: (" << -FLT_MIN <<", " <<-FLT_MAX << ")\n";
cout << "double Range: (" << DBL_MIN <<", " <<DBL_MAX << ")\n";
cout << "double(negative) Range: (" << -DBL_MIN <<", " <<-DBL_MAX << ")";
}输出结果
char Range: (-128, 127) short char Range: (-128, 127) unsigned char Range: (0, 255) short int Range: (-32768, 32767) unsigned short int Range: (0, 65535) int Range: (-2147483648, 2147483647) unsigned int Range: (0, 4294967295) long int Range: (-2147483648, 2147483647) unsigned long int Range: (0, 4294967295) long long int Range: (-9223372036854775808, 9223372036854775807) unsigned long long int Range: (0, 18446744073709551615) float Range: (1.17549e-038, 3.40282e+038) float(negative) Range: (-1.17549e-038, -3.40282e+038) double Range: (2.22507e-308, 1.79769e+308) double(negative) Range: (-2.22507e-308, -1.79769e+308)