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Difference between revisions of "cpp/numeric/math/isnormal"

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< cpp‎ | numeric‎ | math
m (Text replace - "{{mark c++0x feature}}" to "{{mark c++11 feature}}")
m (Minor fix.)
 
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{{cpp/title|isnormal}}
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{{cpp/numeric/math/unary_is|isnormal
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{{cpp/numeric/math/sidebar}}
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|description=Determines if the given floating point number {{c|num}} is normal, i.e. is neither zero, subnormal, infinite, nor NaN.
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{{ddcl list begin}}
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|condition=is normal
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{{ddcl list header | cmath}}
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{{ddcl list item | notes={{mark c++11 feature}} |
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int isnormal( float arg );
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}}
 
}}
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{{ddcl list item | notes={{mark c++11 feature}} |
 
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int isnormal( double arg );
 
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}}
 
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{{ddcl list item | notes={{mark c++11 feature}} |
 
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int isnormal( long double arg );
 
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}}
 
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{{ddcl list end}}
 
  
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Determines if the given floating point number {{tt|arg}} is normal, i.e. is neither zero, subnormal, infinite, nor {{tt|NaN}}. 
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===Example===
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{{example
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|code=
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#include <cfloat>
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#include <cmath>
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#include <iostream>
  
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===Parameters===
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int main()
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{{param list begin}}
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{
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{{param list item | arg | floating point value}}
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    std::cout << std::boolalpha
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{{param list end}}
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              << "isnormal(NaN) = " << std::isnormal(NAN) << '\n'
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              << "isnormal(Inf) = " << std::isnormal(INFINITY) << '\n'
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===Return value===
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              << "isnormal(0.0) = " << std::isnormal(0.0) << '\n'
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              << "isnormal(DBL_MIN/2.0) = " << std::isnormal(DBL_MIN / 2.0) << '\n'
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nonzero value if {{tt|arg}} is normal, {{cpp|0}} otherwise
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              << "isnormal(1.0) = " << std::isnormal(1.0) << '\n';
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}
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|output=
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isnormal(NaN) = false
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isnormal(Inf) = false
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isnormal(0.0) = false
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isnormal(DBL_MIN/2.0) = false
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isnormal(1.0) = true
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}}
  
 
===See also===
 
===See also===
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{{dsc begin}}
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{{dsc inc|cpp/numeric/math/dsc fpclassify}}
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{{dsc inc|cpp/numeric/math/dsc isfinite}}
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{{dsc inc|cpp/numeric/math/dsc isinf}}
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{{dsc inc|cpp/numeric/math/dsc isnan}}
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{{dsc see c|c/numeric/math/isnormal}}
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{{dsc end}}
  
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{{dcl list begin}}
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{{langlinks|de|es|fr|it|ja|pt|ru|zh}}
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{{dcl list template | cpp/numeric/math/dcl list fpclassify}}
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{{dcl list template | cpp/numeric/math/dcl list isfinite}}
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{{dcl list template | cpp/numeric/math/dcl list isinf}}
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{{dcl list template | cpp/numeric/math/dcl list isnan}}
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{{dcl list end}}
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Latest revision as of 17:58, 20 March 2023

 
C++
 
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Defined in header <cmath>
(1)
bool isnormal( float num );

bool isnormal( double num );

bool isnormal( long double num );
 (since C++11)
(until C++23)
constexpr bool isnormal( /* floating-point-type */ num );
 (since C++23)
Defined in header <cmath>
template< class Integer >
bool isnormal( Integer num );
 (A) (since C++11)
(constexpr since C++23)
1) Determines if the given floating point number num is normal, i.e. is neither zero, subnormal, infinite, nor NaN. The library provides overloads for all cv-unqualified floating-point types as the type of the parameter num.(since C++23)
A) Additional overloads are provided for all integer types, which are treated as double.

Contents

[edit] Parameters

num - floating-point or integer value

[edit] Return value

true if num is normal, false otherwise.

[edit] Notes

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::isnormal(num) has the same effect as std::isnormal(static_cast<double>(num)).

[edit] Example

Run this code
#include <cfloat>
#include <cmath>
#include <iostream>
 
int main()
{
    std::cout << std::boolalpha
              << "isnormal(NaN) = " << std::isnormal(NAN) << '\n'
              << "isnormal(Inf) = " << std::isnormal(INFINITY) << '\n'
              << "isnormal(0.0) = " << std::isnormal(0.0) << '\n'
              << "isnormal(DBL_MIN/2.0) = " << std::isnormal(DBL_MIN / 2.0) << '\n'
              << "isnormal(1.0) = " << std::isnormal(1.0) << '\n';
}

Output: 

isnormal(NaN) = false
isnormal(Inf) = false
isnormal(0.0) = false
isnormal(DBL_MIN/2.0) = false
isnormal(1.0) = true

[edit] See also

(C++11)
 categorizes the given floating-point value
(function) [edit]
(C++11)
 checks if the given number has finite value
(function) [edit]
(C++11)
 checks if the given number is infinite
(function) [edit]
(C++11)
 checks if the given number is NaN
(function) [edit]
C documentation for isnormal
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