The C++ clear() member function program example
Compiler: Visual C++ Express Edition 2005
Compiled on Platform: Windows XP Pro SP2
Header file: Standard
Additional library: none/default
Additional project setting: Set project to be compiled as C++
Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C++ Code (/TP)
Other info: none
To do: Using the C++ clear() member function to erase all elements of a string in C++ programming
To show: How to erase all elements of a string in C++ programming using the C++ clear() member function
// the C++ clear() program example
#include <string>
#include <iostream>
using namespace std;
int main(void)
{
string str1("Testing the clear()");
basic_string <char>::iterator StrIter;
// normal
cout<<"(normal read and print) str1 string is: "<<str1<<endl;
// using iterator, iterate character by character
cout<<"(using iterator to read and print) str1 string is: ";
for (StrIter = str1.begin(); StrIter != str1.end(); StrIter++)
cout<<*StrIter;
cout<<endl;
// str1.clear();
cout<<"\nErasing part of the string using erase(13)"<<endl;
str1.erase(13);
cout<<"Operation: str1.erase(13)"<<endl;
cout<<"The modified str1 string is: ";
// using iterator
for(StrIter = str1.begin(); StrIter != str1.end(); StrIter++)
cout<<*StrIter;
cout<<endl;
// for an empty string, begin() is equivalent to end()
cout<<"\nOperation: str1.begin()==str1.end()"<<endl;
if(str1.begin() == str1.end())
cout<<"The str1 string is empty."<<endl;
else
cout<<"The str1 string has some data"<<endl;
// erasing all data
cout<<"\nOperation: str1.erase(13)"<<endl;
cout<<"Erasing all the data using erase()"<<endl;
str1.erase();
// re-check
cout<<"The modified string str1 is: "<<endl;
cout<<"\nOperation: str1.begin()==str1.end()"<<endl;
if(str1.begin() == str1.end())
cout<<"The str1 string is empty."<<endl;
else
cout<<"The str1 string has some data"<<endl;
return 0;
}
Output example:
(normal read and print) str1 string is: Testing the clear()
(using iterator to read and print) str1 string is: Testing the clear()
Erasing part of the string using erase(13)
Operation: str1.erase(13)
The modified str1 string is: Testing the c
Operation: str1.begin()==str1.end()
The str1 string has some data
Operation: str1.erase(13)
Erasing all the data using erase()
The modified string str1 is:
Operation: str1.begin()==str1.end()
The str1 string is empty.
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