std::to_string
Defined in header <string> |
||
---|---|---|
std::string to_string( int value ); |
(1) | (since C++11) |
std::string to_string( long value ); |
(2) | (since C++11) |
std::string to_string( long long value ); |
(3) | (since C++11) |
std::string to_string( unsigned value ); |
(4) | (since C++11) |
std::string to_string( unsigned long value ); |
(5) | (since C++11) |
std::string to_string( unsigned long long value ); |
(6) | (since C++11) |
std::string to_string( float value ); |
(7) | (since C++11) |
std::string to_string( double value ); |
(8) | (since C++11) |
std::string to_string( long double value ); |
(9) | (since C++11) |
Converts a numeric value to std::string
.
1) Converts a signed integer to a string with the same content as what
std::sprintf(buf, "%d", value)
would produce for sufficiently large
buf
.
2) Converts a signed integer to a string with the same content as what
std::sprintf(buf, "%ld", value)
would produce for sufficiently large
buf
.
3) Converts a signed integer to a string with the same content as what
std::sprintf(buf, "%lld", value)
would produce for sufficiently large
buf
.
4) Converts an unsigned integer to a string with the same content as what
std::sprintf(buf, "%u", value)
would produce for sufficiently large
buf
.
5) Converts an unsigned integer to a string with the same content as what
std::sprintf(buf, "%lu", value)
would produce for sufficiently large
buf
.
6) Converts an unsigned integer to a string with the same content as what
std::sprintf(buf, "%llu", value)
would produce for sufficiently large
buf
.
7,8) Converts a floating point value to a string with the same content as what
std::sprintf(buf, "%f", value)
would produce for sufficiently large
buf
.
9) Converts a floating point value to a string with the same content as what
std::sprintf(buf, "%Lf", value)
would produce for sufficiently large
buf
.
Parameters
value | - | a numeric value to convert |
Return value
a string holding the converted value.
Exceptions
May throw std::bad_alloc
from the std::string
constructor.
Notes
- With floating point types
std::to_string
may yield unexpected results as the number of significant digits in the returned string can be zero, see the example. - The return value may differ significantly from what
std::cout
prints by default, see the example. -
std::to_string
relies on the current locale for formatting purposes, and therefore concurrent calls tostd::to_string
from multiple threads may result in partial serialization of calls. C++17 providesstd::to_chars
as a higher-performance locale-independent alternative.
Example
#include <iostream> #include <string> int main() { for (const double f : {23.43, 1e-9, 1e40, 1e-40, 123456789.}) std::cout << "std::cout: " << f << '\n' << "to_string: " << std::to_string(f) << "\n\n"; }
Output:
std::cout: 23.43 to_string: 23.430000 std::cout: 1e-09 to_string: 0.000000 std::cout: 1e+40 to_string: 10000000000000000303786028427003666890752.000000 std::cout: 1e-40 to_string: 0.000000 std::cout: 1.23457e+08 to_string: 123456789.000000
See also
(C++11)
|
converts an integral or floating point value to wstring (function) |
(C++11)(C++11)
|
converts a string to an unsigned integer (function) |
(C++11)(C++11)(C++11)
|
converts a string to a signed integer (function) |
(C++11)(C++11)(C++11)
|
converts a string to a floating point value (function) |
(C++17)
|
converts an integer or floating-point value to a character sequence (function) |
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