list::clear() in C++ STL
Lists are containers used in C++ to store data in a non contiguous fashion, Normally, Arrays and Vectors are contiguous in nature, therefore the insertion and deletion operations are costlier as compared to the insertion and deletion option in Lists.
list::clear()
clear() function is used to remove all the elements of the list container, thus making it size 0.
Syntax :
listname.clear()
Parameters :
No parameters are passed.
Result :
All the elements of the list are
removed ( or destroyed )
Examples:
Input : list{1, 2, 3, 4, 5};
list.clear();
Output : list{}
Input : list{};
list.clear();
Output : list{}
Errors and Exceptions
1. It has a no exception throw guarantee.
2. Shows error when a parameter is passed.
CPP
// CPP program to illustrate // Implementation of clear() function #include <iostream> #include <list> using namespace std; int main() { list< int > mylist{ 1, 2, 3, 4, 5 }; mylist.clear(); // List becomes empty // Printing the list for ( auto it = mylist.begin(); it != mylist.end(); ++it) cout << ' ' << *it; return 0; } |
Output:
No Output
Time Complexity: O(n)
Auxiliary Space: O(1)
Related Article : Delete elements in C++ STL List
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