C$++$ getting error messages : 'ScientificCalculator' is missing exception specification 'noexcept' and Cannot combine with previous 'void' declaration specifier

#include

#include

#include "ScientificCalculator.hpp$"$

using namespace std;

ScientificCalculator::ScientificCalculator$()//$error:'ScientificCalculator' is missing exception specification 'noexcept'

$\{$

$\}$

ScientificCalculator::~ScientificCalculator$()$

$\{$

$\}$

void double ScientificCalculator::sine$($double angle$)//$error:Cannot combine with previous 'void' declaration specifier

$\{$

$$ cout $<<$ "Enter angle: $"$;

$$ cin $>>$ angle;

$$ return sine$($angle$)$;

$\}$

scientificCalculator.h

class ScientificCalculator

$\{$

$$ public:

$$ ~ScientificCalculator$()$;

$$

$$ void sine$($double angle$)$;

$$ void cosine$($double angle$)$;

$$ void tangent$($double angle$)$;

$$ void logarithm$($double value$)$;

$$ void exponent$($double exponent$)$;

$\}$;

#endif