std::string is the C++ standard library's byte-based "string" type, defined in the
Questions tagged [stdstring]
1177 questions
996
votes
51 answers
How to trim an std::string?
I'm currently using the following code to right-trim all the std::strings in my programs:
std::string s;
s.erase(s.find_last_not_of(" \n\r\t")+1);
It works fine, but I wonder if there are some end-cases where it might fail?
Of course, answers with…
Milan Babuškov
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770
votes
25 answers
How to concatenate a std::string and an int
I thought this would be really simple, but it's presenting some difficulties. If I have
std::string name = "John";
int age = 21;
How do I combine them to get a single string "John21"?
Obediah Stane
- 15,471
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618
votes
17 answers
How to replace all occurrences of a character in string?
What is the effective way to replace all occurrences of a character with another character in std::string?
big-z
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610
votes
44 answers
std::string formatting like sprintf
I have to format std::string with sprintf and send it into file stream. How can I do this?
Max Frai
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356
votes
13 answers
convert a char* to std::string
I need to use an std::string to store data retrieved by fgets(). To do this I need to convert the char* return value from fgets() into an std::string to store in an array. How can this be done?
Jonathan Prior
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293
votes
5 answers
Is it possible to use std::string in a constexpr?
Using C++11, Ubuntu 14.04, GCC default toolchain.
This code fails:
constexpr std::string constString = "constString";
error: the type ‘const string {aka const std::basic_string}’ of
constexpr variable ‘constString’ is not literal... because...
…
Vector
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214
votes
20 answers
How do you append an int to a string in C++?
int i = 4;
string text = "Player ";
cout << (text + i);
I'd like it to print Player 4.
The above is obviously wrong but it shows what I'm trying to do here. Is there an easy way to do this or do I have to start adding new includes?
Wawa
157
votes
18 answers
Alternative to itoa() for converting integer to string C++?
I was wondering if there was an alternative to itoa() for converting an integer to a string because when I run it in visual Studio I get warnings, and when I try to build my program under Linux, I get a compilation error.
Tomek
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131
votes
12 answers
How to get the number of characters in a std::string?
How should I get the number of characters in a string in C++?
Elliot
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129
votes
13 answers
What does string::npos mean in this code?
What does the phrase std::string::npos mean in the following snippet of code?
found = str.find(str2);
if (found != std::string::npos)
std::cout << "first 'needle' found at: " << int(found) << std::endl;
boom
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128
votes
7 answers
Legality of COW std::string implementation in C++11
It had been my understanding that copy-on-write is not a viable way to implement a conforming std::string in C++11, but when it came up in discussion recently I found myself unable to directly support that statement.
Am I correct that C++11 does not…
acm
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124
votes
22 answers
How to implode a vector of strings into a string (the elegant way)
I'm looking for the most elegant way to implode a vector of strings into a string. Below is the solution I'm using now:
static std::string& implode(const std::vector& elems, char delim, std::string& s)
{
for…
ezpresso
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111
votes
6 answers
How to convert std::string to NSString?
I am trying to convert a standard std::string into an NSString but I'm not having much luck.
I can convert successfully from an NSString to a std::string with the following code
NSString *realm = @"Hollywood";
std::string REALM = [realm…
Anthony McCormick
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110
votes
4 answers
How to efficiently get a `string_view` for a substring of `std::string`
Using http://en.cppreference.com/w/cpp/string/basic_string_view as a reference, I see no way to do this more elegantly:
std::string s = "hello world!";
std::string_view v = s;
v = v.substr(6, 5); // "world"
Worse, the naive approach is a pitfall…
sehe
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108
votes
11 answers
How do you construct a std::string with an embedded null?
If I want to construct a std::string with a line like:
std::string my_string("a\0b");
Where i want to have three characters in the resulting string (a, null, b), I only get one. What is the proper syntax?
Bill
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