std::string::append() in C++

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// 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 codeint 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.
// 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 codeint 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
// CPP code to demonstrate append(const char* cstr)  #include <iostream>#include <string>using namespace std;   // Function to demonstrate appendvoid appendDemo(string str){    // Appends "GeeksforGeeks"    // in str    str.append("GeeksforGeeks");    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint 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.
// CPP code to demonstrate // (const char* chars, size_type chars_len)  #include <iostream>#include <string>using namespace std;   // Function to demonstrate appendvoid appendDemo(string str){    // Appends 5 characters from "GeeksforGeeks"    // to str    str.append("GeeksforGeeks", 5);    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint 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.
// CPP code to illustrate// string& string::append (size_type num, char c)    #include <iostream>#include <string>using namespace std;    // Function to demonstrate appendvoid appendDemo(string str){    // Appends 10 occurrences of '$'    // to str    str.append(10, '$');    cout << "After append() : ";    cout << str;   }           // Driver codeint 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 appendvoid 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 codeint 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

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 codeint 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

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 codeint 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.
// 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 codeint 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

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 codeint 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
// CPP code to demonstrate append(const char* cstr)  #include <iostream>#include <string>using namespace std;   // Function to demonstrate appendvoid appendDemo(string str){    // Appends "GeeksforGeeks"    // in str    str.append("GeeksforGeeks");    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint main(){    string str("World of ");       cout << "Original String : " << str << endl;    appendDemo(str);       return 0;}Output:Original String : World of 
Using append() : World of GeeksforGeeks

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 appendvoid appendDemo(string str){    // Appends "GeeksforGeeks"    // in str    str.append("GeeksforGeeks");    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint 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.
// CPP code to demonstrate // (const char* chars, size_type chars_len)  #include <iostream>#include <string>using namespace std;   // Function to demonstrate appendvoid appendDemo(string str){    // Appends 5 characters from "GeeksforGeeks"    // to str    str.append("GeeksforGeeks", 5);    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint main(){    string str("World of ");       cout << "Original String : " << str << endl;    appendDemo(str);       return 0;}Output:Original String : World of 
Using append() : World of Geeks

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 appendvoid appendDemo(string str){    // Appends 5 characters from "GeeksforGeeks"    // to str    str.append("GeeksforGeeks", 5);    cout << "Using append() : ";    cout << str << endl;}   // Driver codeint 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.
// CPP code to illustrate// string& string::append (size_type num, char c)    #include <iostream>#include <string>using namespace std;    // Function to demonstrate appendvoid appendDemo(string str){    // Appends 10 occurrences of '$'    // to str    str.append(10, '$');    cout << "After append() : ";    cout << str;   }           // Driver codeint main(){    string str("#########");       cout << "Original String : " << str << endl;    appendDemo(str);        return 0;}Output:Original String : #########
After append() : #########$$$$$$$$$$

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 appendvoid appendDemo(string str){    // Appends 10 occurrences of '$'    // to str    str.append(10, '$');    cout << "After append() : ";    cout << str;   }           // Driver codeint 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 appendvoid 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 codeint 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

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 appendvoid 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 codeint 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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