std::string::append() in C++
Last Updated :
06 Jul, 2017
This member function appends characters in the end of string.
-
Syntax 1 : Appends the characters of string str. It Throws length_error if the resulting size exceeds the maximum number of characters.
string& string::append (const string& str)
str : is the string to be appended.
Returns : *this
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str1, string str2)
{
str1.append(str2);
cout << "Using append() : " ;
cout << str1 << endl;
}
int main()
{
string str1( "Hello World! " );
string str2( "GeeksforGeeks" );
cout << "Original String : " << str1 << endl;
appendDemo(str1, str2);
return 0;
}
|
Output:
Original String : Hello World!
Using append() : Hello World! GeeksforGeeks
- Syntax 2 : Appends at most, str_num characters of string str, starting with index str_idx. It throws out_of_range if str_idx > str. size(). It throws length_error if the resulting size exceeds the maximum number of characters.
string& string::append (const string& str, size_type str_idx, size_type str_num)
str : is the string to be appended
str_num : being number of characters
str_idx : is index number.
Returns : *this.
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str1, string str2)
{
str1.append(str2, 0, 5);
cout << "Using append() : " ;
cout << str1;
}
int main()
{
string str1( "GeeksforGeeks " );
string str2( "Hello World! " );
cout << "Original String : " << str1 << endl;
appendDemo(str1, str2);
return 0;
}
|
Output:
Original String : GeeksforGeeks
Using append() : GeeksforGeeks Hello
- Syntax 3: Appends the characters of the C-string cstr. Throw length_error if the resulting size exceeds the maximum number of characters.
string& string::append (const char* cstr)
*cstr : is the pointer to C-string.
Note : that cstr may not be a null pointer (NULL).
Return : *this
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str)
{
str.append( "GeeksforGeeks" );
cout << "Using append() : " ;
cout << str << endl;
}
int main()
{
string str( "World of " );
cout << "Original String : " << str << endl;
appendDemo(str);
return 0;
}
|
Output:
Original String : World of
Using append() : World of GeeksforGeeks
- Syntax 4: Appends chars_len characters of the character array chars. Throws length_error if the resulting size exceeds the maximum number of characters.
string& string::append (const char* chars, size_type chars_len)
*chars is the pointer to character array to be appended.
chrs_len : is the number of characters from *chars to be appended.
Note that chars must have at least chars_len characters.
Returns : *this.
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str)
{
str.append( "GeeksforGeeks" , 5);
cout << "Using append() : " ;
cout << str << endl;
}
int main()
{
string str( "World of " );
cout << "Original String : " << str << endl;
appendDemo(str);
return 0;
}
|
Output:
Original String : World of
Using append() : World of Geeks
- Syntax 5: Appends num occurrences of character c. Throws length_error if the resulting size exceeds the maximum number of characters.
string& string::append (size_type num, char c)
num : is the number of occurrences
c : is the character which is to be appended repeatedly.
Returns : *this.
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str)
{
str.append(10, '$' );
cout << "After append() : " ;
cout << str;
}
int main()
{
string str( "#########" );
cout << "Original String : " << str << endl;
appendDemo(str);
return 0;
}
|
Output:
Original String : #########
After append() : #########$$$$$$$$$$
- Syntax 6: Appends all characters of the range [beg, end). Throws length_error if the resulting size exceeds the maximum number of characters.
string& string::append (InputIterator beg, InputIterator end)
first, last : Input iterators to the initial and final positions
in a sequence.
Returns *this.
#include <iostream>
#include <string>
using namespace std;
void appendDemo(string str1, string str2)
{
str1.append(str2.begin() + 5, str2.end());
cout << "Using append : " ;
cout << str1;
}
int main()
{
string str1( "Hello World! " );
string str2( "GeeksforGeeks" );
cout << "Original String : " << str1 << endl;
appendDemo(str1, str2);
return 0;
}
|
Output:
Original String : Hello World!
Using append : Hello World! forGeeks
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