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Difference between revisions of "cpp/string/basic string/push back"

From cppreference.com
< cpp‎ | string‎ | basic string
m (Text replace - "<!-- ======== --> " to "")
m (→Synopsis: {{ddcla}}; →Defect reports: "(1)" => "1)" cuz former is mostly reserved to refer to overloads.)
 
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{{cpp/string/basic_string/title | push_back}}
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{{cpp/string/basic_string/title|push_back}}
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{{cpp/string/basic_string/sidebar}}
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{{cpp/string/basic_string/navbar}}
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{{ddcl |
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{{ddcla|constexpr=c++20|
 
void push_back( CharT ch );
 
void push_back( CharT ch );
 
}}
 
}}
  
−
Appends the given character {{tt|ch}} to the end of the string.
+
Appends the given character {{c|ch}} to the end of the string.
  
 
===Parameters===
 
===Parameters===
−
{{param list begin}}
+
{{par begin}}
−
{{param list item | ch | the character to append}}
+
{{par|ch|the character to append}}
−
{{param list end}}  
+
{{par end}}  
  
 
===Return value===
 
===Return value===
−
{{return none}}
+
(none)
  
 
===Complexity===
 
===Complexity===
−
{{complex constant}}.
+
Amortized constant.
 +
 
 +
===Exceptions===
 +
{{cpp/string/basic_string/length error note}}
 +
 
 +
{{cpp/strong exception safety guarantee}}
 +
 
 +
===Example===
 +
{{example
 +
|code=
 +
#include <iomanip>
 +
#include <iostream>
 +
#include <string>
 +
 
 +
int main()
 +
{
 +
    std::string str{"Short string"};
 +
    std::cout << "1) " << std::quoted(str) << ", size: " << str.size() << '\n';
 +
   
 +
    str.push_back('!');
 +
    std::cout << "2) " << std::quoted(str) << ", size: " << str.size() << '\n';
 +
}
 +
|output=
 +
1) "Short string", size: 12
 +
2) "Short string!", size: 13
 +
}}
 +
 
 +
===Defect reports===
 +
{{dr list begin}}
 +
{{dr list item|wg=lwg|dr=7|std=C++98|before=1) the description was missing in the C++ standard<br>2) the parameter type was {{c/core|const CharT}}|after=1) description added<br>2) changed to {{tt|CharT}}}}
 +
{{dr list item|wg=lwg|dr=847|std=C++98|before=there was no exception safety guarantee|after=added strong exception safety guarantee}}
 +
{{dr list end}}
  
 
===See also===
 
===See also===
 +
{{dsc begin}}
 +
{{dsc inc|cpp/string/basic_string/dsc pop_back}}
 +
{{dsc end}}
  
−
{{dcl list begin}}
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{{langlinks|de|es|fr|it|ja|pt|ru|zh}}
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{{dcl list template | cpp/string/basic_string/dcl list pop_back}}
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−
{{dcl list end}}
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Latest revision as of 14:04, 18 October 2024

 
C++
 
Strings library
 
std::basic_string
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(C++23)
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(C++23)
basic_string::push_back
(DR*)
(C++23)
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void push_back( CharT ch );
 (constexpr since C++20)

Appends the given character ch to the end of the string.

Contents

[edit] Parameters

ch - the character to append

[edit] Return value

(none)

[edit] Complexity

Amortized constant.

[edit] Exceptions

If the operation would result in size() > max_size(), throws std::length_error.

If an exception is thrown for any reason, this function has no effect (strong exception safety guarantee).

[edit] Example

Run this code
#include <iomanip>
#include <iostream>
#include <string>
 
int main()
{
    std::string str{"Short string"};
    std::cout << "1) " << std::quoted(str) << ", size: " << str.size() << '\n';
 
    str.push_back('!');
    std::cout << "2) " << std::quoted(str) << ", size: " << str.size() << '\n';
}

Output: 

1) "Short string", size: 12
2) "Short string!", size: 13

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 7 C++98 1) the description was missing in the C++ standard
2) the parameter type was const CharT 		1) description added
2) changed to CharT
LWG 847 C++98 there was no exception safety guarantee added strong exception safety guarantee

[edit] See also

(DR*)
 removes the last character
(public member function) [edit]
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