Erases all elements from the container. After this call,size() returns zero.

Invalidates any references, pointers, and iterators referring to contained elements.Any past-the-end iterators are also invalidated.

[edit]Complexity

Linear in the size of the container, i.e., the number of elements.

Notes

Callingclear() does not affect the result ofcapacity(). The standard's restriction on the changes to capacity is in the specification ofreserve(), seeSO.

[edit]Example

#include <iostream>#include <string_view>#include <vector> void print_info(std::string_view rem,conststd::vector<int>& v){std::cout<< rem<<"{ ";for(constauto& value: v)std::cout<< value<<' ';std::cout<<"}\n";std::cout<<"Size="<< v.size()<<", Capacity="<< v.capacity()<<'\n';} int main(){std::vector<int> container{1,2,3};    print_info("Before clear: ", container);    container.clear();    print_info("After clear: ", container);}

Before clear: { 1 2 3 }Size=3, Capacity=3After clear: { }Size=0, Capacity=3

Defect reports

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

[edit]See also

• In other languages

• Deutsch
• Español
• Français
• Italiano
• 日本語
• Português
• Русский
• 中文