Updated April 14, 2023
What is C++ push_back?
push_back method() in C++ is a method that is part of the vector as a data structure in C++. It is used for pushing elements from the back of the vector. Any new element is inserted into the vector from the end of the vector just after the last or the present element is inserted into the vector thus increasing the size of the vector by one. Push_back method is inevitable without vector it is majorly supported by a vector as a data structure and standard library to perform manipulation with the elements within the array.
Syntax:
Name_Of_Vector.push_back(argument)The syntax flow is in a way as represented :
- Name_Of_Vector: As its name suggests the Name_Of_Vector is given as a C++ initial.
- Push_back: This represents push_back as a function.
- argument: It represents a parameter that is passed to the function at the end of vector.
There is no return type for push_back function as it doesn’t perform any major functionality with more complexity.
How push_back Method Works in C++?
push_back() method is one method in C++ which is part of the standard library supporting vector whose main task is to insert any new element at the end of the vector being defined or declared. Inserting a new element at the end of the vector using push_back function increase the size of the entire vector by one. This has no complexity except for the fact that the element newly inserted gets inserted into the vector from one end and then makes the entire vector useful for the end-user. Programmers can easily and efficiently make use of this functionality as it is a build-in function with respect to the standard library. There is no requirement of passing parameters to the function as it will just describe and give an insight of the type of element which will be inserted into the vector. There is no return type in the push_back method of C++. Member function never throws the exception for this function of push_back() method in C++. Also, the time complexity is constant because data structure i.e. vector does not require much manipulation with the internal components or pointer manipulation with respect to the elements beside for a task which is insertion and deletion of elements that happen only from one end of the entire vector. There Is no parameter that is passed with the function itself until any external function or parameter is sent that is also just adding and inserting element from back of the vector which has nothing to do with external parameter manipulation rather this method will always remain user friendly. After insertion and adding an element at the back of the vector will make an entire vector increase its size by one. Since there is no complex functionality except adding and deleting the elements push_back function does not possess any return type. This function has one more good advantage which is like it never throws any exception and thus let programmers work seamlessly using the function directly from the standard library and then providing ample simplicity as the time complexity of the function is also constant.
One more distinction can also be brought into picture which says that the vectors in C++ acts like a container therefore on comparison it can be seen that the array size and declaration must be made at the time of compile time whereas the case with vectors is not same because in case of vectors memory allocation is already declared pre-handedly just to make sure that multiple objects can be placed at different memory locations. As explained before containers are abstract data types in C++ that provides a vision to programmers to make use of the stored multiple objects and follow certain norms to access all elements from the vector. There are ways to manipulate with these vectors which include the creation of Objects, deleting objects, and accessing elements within a vector. Vector supports the push_back() method which is a build-in function for standard library associated with vectors. In later versions of C++ 11, the go to the implementation of push_back function with vector got changed where the method has been reduced to allocate data types at the time of compilation itself at the time of inserting element from back of vector. Push_back supporting vectors can be used with different data types including int, string, float, and 2D vector. Using push_back function is an extremely inexpensive task to be performed as it does not include much of task except for manipulation.
Examples of C++ push_back
Following are the examples of c++ push_back as given below:
Example #1
This program demonstrates the push_back method in C++ which is used for inserting new elements from back of the vector thus increasing the size of a vector by one as shown in the output.
Code:
#include <iostream>
#include <vector>
using namespace std;
int main()
{
vector<int> m_vctr{ 5,6,7,8,9 };
m_vctr.push_back(7);
for (auto ptu = m_vctr.begin(); ptu != m_vctr.end(); ++ptu)
cout << ' ' << *ptu;
}Output:
Example #2
This program demonstrates the push_back method in C++ which is used for inserting new elements from back of the list as data structure thus increasing the size of list by one as shown in the output.
Code:
#include <bits/stdc++.h>
using namespace std;
int main()
{
list<int> dm_lst;
cout << "Actual_Size: "
<< dm_lst.size() << endl;
dm_lst.push_back(8);
dm_lst.push_back(6);
dm_lst.push_back(9);
cout << "After_Adding_elements "
<< "All_elements: " << dm_lst.size();
return 0;
}Output:
Advantages
There are numerous advantages associated with push_back function of C++ which are illustrated as follows :
- Programmers get the flexibility and easy to insert elements at the back of the vector or list as a data structure.
- All the functions present are inbuild function which makes it as simple and easy from an accessibility point of view.
- The complexity of the push_back function is constant which is the much-needed complexity by programmers in terms of implementation.
Conclusion
Push_back() method in C++ is quite a versatile and simple method in terms of manipulation of elements with the insertion of elements within the vector or list as a data structure. It is supported by many different data types which is quite an interesting feature of push_back function in C++ and desired by many programmers.
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