Prior to C++11, there is no built-in function in C++ standard library which can be used to convert numbers such as interger and double number to string. There are many ways which can convert number to string. Since C++ is C compatible, we can use itoa() function to convert an integer to C style string. But this one can only convert integer to string, not double. For different types of numbers, we need to use different functions.
string s = string(itoa(a));Actually, we can also use stringstream in C++ to convert number to string. Also, here since we want to convert different types of numbers to string, we may need template. Below is the implementation:
/*
* Method : toString()
* Description : Convert other data type to string
* Input : T -- template data type
* Return : string
*/
template
static string toString(T data){
stringstream s;
s<<data;
return s.str();
}
So later when we want to convert an integer or double number to string, we can use it this way.
toString(42);
toString(42.01);
toString("42");
Fortunately, in C++11, we can use the built-in std::to_string() method to convert number to string. The overloaded types defined are:
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std::string to_string( int value );
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(1) | (since C++11) |
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std::string to_string( long value );
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(2) | (since C++11) |
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std::string to_string( long long value );
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(3) | (since C++11) |
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std::string to_string( unsigned value );
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(4) | (since C++11) |
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std::string to_string( unsigned long value );
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(5) | (since C++11) |
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std::string to_string( unsigned long long value );
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(6) | (since C++11) |
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std::string to_string( float value );
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(7) | (since C++11) |
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std::string to_string( double value );
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(8) | (since C++11) |
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std::string to_string( long double value );
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(9) | (since C++11) |
For example:
double f = 23.43; std::string f_str = std::to_string(f);
Reference : http://en.cppreference.com/w/cpp/string/basic_string/to_string
