c语言的极限值的问题
1、类型 下限 上限
char CHAR_MIN CHAR_MAX
short SHRT_MIN SHRT_MAX
int INT_MIN INT_MAX
long LONG_MIN LONG_MAX
long long LLONG_MIN LLONG_MAX
无符号下限是0 U CHAR_MAX USHRT_MAX U INT_MAX ULONG_MAX ULLONG_MAX
例如 int number = INT_MAX ;

2、<float.h>头文件定义了表示浮点数的符号
类型 下限 上限
float FLT_MIN FLT_MAX
double DBL_MAX DBL_MAX
long double LDBL_MIN LDBL_MAX

3、例子:
/* Program 2.11 Finding the limits */
#include <stdio.h> /* For command line input and output */
#include < limits.h > /* For limits on integer types */
#include <float.h> /* For limits on floating-point types */
int main(void)
{
printf("Variables of type char store values from %d to %d",
CHAR_MIN, CHAR_MAX);
printf("\nVariables of type unsigned char store values from 0 to %u",
UCHAR_MAX);
printf("\nVariables of type short store values from %d to %d",
SHRT_MIN, SHRT_MAX);
printf("\nVariables of type unsigned short store values from 0 to %u",
USHRT_MAX);
printf("\nVariables of type int store values from %d to %d", INT_MIN, INT_MAX);
printf("\nVariables of type unsigned int store values from 0 to %u", UINT_MAX);
printf("\nVariables of type long store values from %ld to %ld",
LONG_MIN, LONG_MAX);
printf("\nVariables of type unsigned long store values from 0 to %lu",
ULONG_MAX);
printf("\nVariables of type long long store values from %lld to %lld",
LLONG_MIN, LLONG_MAX);
printf("\nVariables of type unsigned long long store values from 0 to %llu",
ULLONG_MAX);
printf("\n\nThe size of the smallest non-zero value of type float is %.3e",
FLT_MIN);
printf("\nThe size of the largest value of type float is %.3e", FLT_MAX);
printf("\nThe size of the smallest non-zero value of type double is %.3e",
DBL_MIN);
printf("\nThe size of the largest value of type double is %.3e", DBL_MAX);
printf("\nThe size of the smallest non-zero value of type long double is %.3Le",
LDBL_MIN);
printf("\nThe size of the largest value of type long double is %.3Le\n",
LDBL_MAX);
printf("\nVariables of type float provide %u decimal digits precision.",
FLT_DIG);
printf("\nVariables of type double provide %u decimal digits precision.",
DBL_DIG);
printf("\nVariables of type long double provide %u decimal digits precision.",
LDBL_DIG);
return 0;
}
摘自《C语言入门经典》第4版