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The distinction between the C++ copy constructor and assignment operator

The object-oriented programming idea is supported by the general-purpose, middle-level, case-sensitive, platform agnostic computer language C++. Bjarne Stroustrup developed the C++ programming language in 1979 at Bell Laboratories. Since C++ is a platform-independent programming language, it may be used on a wide range of operating systems, including Windows, Mac OS, and different UNIX versions.

Assignment operators are used to assign values to variables from the aforementioned groups.

Let's first study a little bit about constructors before moving on to copy constructors. When an object is formed, a specific method called a constructor-which has the same name as the class name with the parentheses "()"-is automatically called. Initializing the variables of a freshly generated object is done using the constructor.

A copy constructor is a form of constructor that uses an already-created object from the same class to initialize a new object.

Let's now go over the specifics of the notion and contrast and compare the features of the assignment operator and copy constructor.

Describe the assignment operator

The assignment operator is used to give a variable a value. The assignment operator has a variable name as its left operand and a value to that variable as its right operand. A compilation error will be triggered if neither operand's datatype matches the other.

Assignment operators come in various forms.

: = operator Only the value is given to the variable. For instance, if "a=10," variable "a" will be given the value of 10.

The += operator first multiplies the variable's current value by the value on the right side before assigning the new value.

The operator "-=" first subtracts the variable's current value from the value on the right side before appending the new value.

In order to assign a new value to a variable, the *= operator first multiplies the variable's current value by the value on the right side.

The operator /= first divides the variable's current value by the value on the right side before assigning the new value to the variable.

Illustration of Assignment Operator

Below is an illustration of an assignment operator. The assignment operator is being used in this case to give values to several variables.


The two variables "a" and "b" were used in the example above, and we first set the value of "a" to 5 using the assignment operator "=". And we've given variable b the value of the a variable. The output from the aforementioned code is shown below.

The value of a is 5.
The value of b is 5.

What is a Copy Constructor?

Programmers frequently need to do this in order to duplicate an object without affecting the original. The copy constructor is used in these circumstances. The copy constructor produces an object by initializing it with a different object of the same class that has already been constructed. The copy constructor comes in two varieties.

The default copy constructor is created by the C++ compiler when the copy constructor is not declared, and it copies all member variables exactly as they are.

User-Defined Copy Constructor: This term refers to a copy constructor that has been defined by the user.


The syntax for Copy Constructor is -

Comparison of the Assignment Operator and the Copy Constructor

All of these C++ concepts' primary functions are to assign values, but the key distinction between them is that while the copy constructor produces a new object and assigns the value, the assignment operator assigns the value to the data member of the same object rather than to a new object.

The key distinctions between assignment operator and copy constructor are shown in the following table.

Copy constructor Assignment operator
An example of an overloaded constructor is the copy constructor.
A new object is initialized by an existing object of the same type using the copy constructor.

An operator that assigns a value to objects or data members is known as an assignment operator.
It transfers an object's value from one produced object to another.
When an old object is used to initialize a new one, as well as when the object is supplied to a function as a non-reference parameter, the copy constructor is called. When an old object's value is transferred to a new object, the assignment operator is used.
The newly invoked object will share distinct memory addresses with the previously generated object. The first object and the second object, to whom the first object's value is assigned, share the same memory addresses.

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