public member function
<string>
const char* c_str() const;
const char* c_str() const noexcept;
Get C string equivalent
This array includes the same sequence of characters that make up the value of the '\0') at the end.
A program shall not alter any of the characters in this sequence.
Both string::c_str are synonyms and return the same value.
The pointer returned points to the internal array currently used by the string object to store the characters that conform its value.Both string::data andare synonyms and return the same value.
The pointer returned may be invalidated by further calls to other member functions that modify the object.
Returns a pointer to an array that contains a null-terminated sequence of characters (i.e., a C-string) representing the current value of the string object.This array includes the same sequence of characters that make up the value of the string object plus an additional terminating null-character () at the end.The pointer returned may be invalidated by further calls to other member functions that modify the object.
Tóm Tắt
Parameters
none
Return Value
A pointer to the c-string representation of the
A pointer to the c-string representation of the string object’s value.
Example
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// strings and c-strings
#include <iostream>
#include <cstring>
#include <string>
int main ()
{
std::string str ("Please split this sentence into tokens");
char * cstr = new char [str.length()+1];
std::strcpy (cstr, str.c_str());
// cstr now contains a c-string copy of str
char * p = std::strtok (cstr," ");
while (p!=0)
{
std::cout << p << '\n';
p = std::strtok(NULL," ");
}
delete[] cstr;
return 0;
}
Output:
Please split this sentence into tokens
Output:
Complexity, iterator, access, exceptions
Unspecified or contradictory specifications.
Complexity
Constant.
Iterator validity
No changes.
Data races
The object is accessed.
Exception safety
No-throw guarantee: this member function never throws exceptions.