std::string::append() in C++
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
// CPP code to demonstrate append(str)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append()
void
appendDemo(string str1, string str2)
{
// Appends str2 in str1
str1.append(str2);
cout <<
"Using append() : "
;
cout << str1 << endl;
}
// Driver code
int
main()
{
string str1(
"Hello World! "
);
string str2(
"w3wiki"
);
cout <<
"Original String : "
<< str1 << endl;
appendDemo(str1, str2);
return
0;
}
Output:
Original String : Hello World! Using append() : Hello World! w3wiki
- 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.
// CPP code to demonstrate
// append(const char* chars, size_type chars_len)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append()
void
appendDemo(string str1, string str2)
{
// Appends 5 characters from 0th index of
// str2 to str1
str1.append(str2, 0, 5);
cout <<
"Using append() : "
;
cout << str1;
}
// Driver code
int
main()
{
string str1(
"w3wiki "
);
string str2(
"Hello World! "
);
cout <<
"Original String : "
<< str1 << endl;
appendDemo(str1, str2);
return
0;
}
Output:
Original String : w3wiki Using append() : w3wiki 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
// CPP code to demonstrate append(const char* cstr)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append
void
appendDemo(string str)
{
// Appends "w3wiki"
// in str
str.append(
"w3wiki"
);
cout <<
"Using append() : "
;
cout << str << endl;
}
// Driver code
int
main()
{
string str(
"World of "
);
cout <<
"Original String : "
<< str << endl;
appendDemo(str);
return
0;
}
Output:
Original String : World of Using append() : World of w3wiki
- 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.
// CPP code to demonstrate
// (const char* chars, size_type chars_len)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append
void
appendDemo(string str)
{
// Appends 5 characters from "w3wiki"
// to str
str.append(
"w3wiki"
, 5);
cout <<
"Using append() : "
;
cout << str << endl;
}
// Driver code
int
main()
{
string str(
"World of "
);
cout <<
"Original String : "
<< str << endl;
appendDemo(str);
return
0;
}
Output:
Original String : World of Using append() : World of Beginner
- 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.
// CPP code to illustrate
// string& string::append (size_type num, char c)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append
void
appendDemo(string str)
{
// Appends 10 occurrences of '$'
// to str
str.append(10,
'$'
);
cout <<
"After append() : "
;
cout << str;
}
// Driver code
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.
// CPP code to illustrate
// append (InputIterator beg, InputIterator end)
#include <iostream>
#include <string>
using
namespace
std;
// Function to demonstrate append
void
appendDemo(string str1, string str2)
{
// Appends all characters from
// str2.begin()+5, str2.end() to str1
str1.append(str2.begin() + 5, str2.end());
cout <<
"Using append : "
;
cout << str1;
}
// Driver code
int
main()
{
string str1(
"Hello World! "
);
string str2(
"w3wiki"
);
cout <<
"Original String : "
<< str1 << endl;
appendDemo(str1, str2);
return
0;
}
Output:
Original String : Hello World! Using append : Hello World! forBeginner
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