String concatenation refers to the collection of characters that join two additional strings to produce a concatenated single string. While concatenating the strings, the second string is appended to the end of the first string to form a single string.
Example:
Example
Input1: st1="Over",st2="loading"
Output: Overloading
Input1: st1="Left",st2="Join"
Output: LeftJoin
Approach 1: By using the Unary Operator Overloading
- Unary operator overloading is used to concatenate two strings. Create a class that has two string parameters.
- Please create a new instance of the class and use its parameterized constructor to initialize the two string parameters with the main function's input values.
- Use the unary operator + to combine these two string parameters for a class instance.
- Finally, use the operator method to join two class variables.
The previously mentioned technique is implemented as follows:
Example:
Filename: OperatorOverloading.cpp
Example
//Concatenation of two strings in C++ by using the unary operator overloading
#include <iostream>
#include <string.h>
using namespace std;
//// method for string concatenation // class to implement overloading of operators
class AddingString {
public:
// the string objects declarations
char st1[25], st2[25];
//the parameterized constructor
AddingString(char string1[], char string2[])
{
// the initialization of the string objects
strcpy(this->st1, string1);
strcpy(this->st2, string2);
}
//the operator for overloading
void operator+()
{
cout << "\nThe Concatenation form of the string: " << strcat(st1, st2);
}
};
int main()
{
// the string declaration
char string1[] = "Operator";
char string2[] = "Overloading";
// Declaring and setting up the class // using the two strings mentioned above
AddingString op(string1, string2);
// operator calling function
+op;
return 0;
}
Output:
Output
The Concatenation form of the string: OperatorOverloading
Explanation:
- In this example, a class called AddingString is used to concatenate strings. It stores the input strings in two member variables, st1 and st2 . The supplied strings are used by the constructor AddingString for initializing st1 and st2. The operator "+ "function has been overloaded to use strcat to conduct string concatenation and show the result.
- Two strings, string1, and string2, are initialized by the main function. Using string1 and string2, it generates an object op of the AddingString The concatenation is then started, and the result is printed by calling the operator "+" function with the unary "+" operator using the op object.
Approach 2: By using binary operator overloading
Create a class that has a string variable and an operator function called "+" that takes an instance of the class's members as input and combines the variable of that instance with the present instance's string variable.
Make two separate instances of the class and initialize both of the input strings in each instance's class variable.
The class variable of each of the instances should now be concatenated using the overloading operator (+) function.
Example:
Filename:Binary.cpp
Example
// A C++ program that uses binary operator overloading for combining two strings
#include <iostream>
#include <string.h>
using namespace std;
// A class that implements the operator overloading method // to join strings together
class AddingString {
public:
// the class having the string object
char str[100];
// no parameters have passed
AddingString() {}
//The constructor having the parameters
AddingString(char strs[])
{
strcpy(this->str, strs);
}
// the operator + is overloaded
AddingString operator+(AddingString& st2)
{
// the copy of the constructor
AddingString st3;
// by using the inbuilt method to add
strcat(this->str, st2.str);
// copying of the strin
strcpy(st3.str, this->str);
// an objecct is returned
return st3;
}
};
// Driver Code
int main()
{
//two string variables declaration
char strs1[] = "Programming";
char strs2[] = "Subjects";
// a class declared and also initialized in the AddingString class
AddingString st1(strs1);
AddingString st2(strs2);
AddingString st3;
// the operator is calling
st3 = st1 + st2;
cout << "The Concatenated form of the string is: " << st3.str;
return 0;
}
Output:
Output
The Concatenated form of the string is: ProgrammingSubjects