# std::numeric_limits<T>::min_exponent

From cppreference.com
< cpp‎ | types‎ | numeric limits

static const int min_exponent; |  | (until C++11)
static constexpr int min_exponent; |  | (since C++11)

The value of std::numeric_limits<T>::min_exponent is the lowest negative number n such that \(\scriptsize r^{n-1}\)rn-1
, where r is std::numeric_limits<T>::radix, is a valid normalized value of the floating-point type `T`.

### Standard specializations

`T` | value of std::numeric_limits<T>::min_exponent
/* non-specialized */ | ​0​
bool | ​0​
char | ​0​
signed char | ​0​
unsigned char | ​0​
wchar_t | ​0​
char8_t (since C++20) | ​0​
char16_t (since C++11) | ​0​
char32_t (since C++11) | ​0​
short | ​0​
unsigned short | ​0​
int | ​0​
unsigned int | ​0​
long | ​0​
unsigned long | ​0​
long long (since C++11) | ​0​
unsigned long long (since C++11) | ​0​
float | FLT_MIN_EXP
double | DBL_MIN_EXP
long double | LDBL_MIN_EXP

### Example

Demonstrates the relationships of `min_exponent`, min_exponent10, min(), and radix for the type float:

Run this code

    #include <iostream>
    #include <limits>

    int main()
    {
        std::cout << "min() = " << std::numeric_limits<float>::min() << '\n'
                  << "min_exponent10 = " << std::numeric_limits<float>::min_exponent10 << '\n'
                  << std::hexfloat << '\n'
                  << "min() = " << std::numeric_limits<float>::min() << '\n'
                  << "min_exponent = " << std::numeric_limits<float>::min_exponent << '\n';
    }

Output:

    min() = 1.17549e-38
    min_exponent10 = -37

    min() = 0x1p-126
    min_exponent = -125

### See also

radix [static] | the radix or integer base used by the representation of the given type (public static member constant)
min_exponent10 [static] | the smallest negative power of ten that is a valid normalized floating-point value (public static member constant)
max_exponent [static] | one more than the largest integer power of the radix that is a valid finite floating-point value (public static member constant)
max_exponent10 [static] | the largest integer power of 10 that is a valid finite floating-point value (public static member constant)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/types/numeric_limits/min_exponent&oldid=148429"