As we know that the C++ programming language offers various useful features and functionalities to the programmers. In C++, Vectors are one of the important and exciting features. You can say that vectors are the same as the array. When an element is inserted or deleted, it can automatically resize itself.<\/p>\n
IN C++, vectors are dynamic arrays that are used to store data. It is capable of resizing itself automatically. When you insert or delete an element then the resizing takes place. Arrays are static in nature and also it is used to store sequential data. But vectors offer more flexibility and efficiency to the program.<\/p>\n
In vectors, the storage is handled automatically by the containers. The elements of the vectors are stored in contiguous storage. That\u2019s why it becomes easy to access and traverse the vector elements using iterators.<\/p>\n
No, vectors are not ordered in C++. If you insert data then that data will be inserted at the end of it. So, it takes different times to insert data at the end and sometimes there may be a need to extend the vector. You can easily traverse and access the vector elements using iterators because they are stored in adjacent storage.<\/p>\n
Arrays are static in nature. It means that you cannot change the size at runtime. But vectors are dynamic in nature. While inserting or deleting an element, it automatically resizes itself.<\/p>\n
You can make use of vectors on the following situations:-<\/p>\n
Syntax:-<\/strong><\/p>\n First, we have to use the vector keyword at the beginning. Then, mention the data type of the elements which will be stored in vectors. Then, provide the name of the vector or the data elements. The items specify the number of elements for the vector’s data.<\/p>\n Below, we created a blank vector:-<\/p>\n Vectors are dynamic in nature.<\/p>\n In STL, a vector container offers various useful functions.<\/p>\n Mainly used to change the meaning of the specified data type. Below are the common modifiers in C++:-<\/p>\n Example:-<\/strong><\/p>\n Output:-<\/strong><\/p>\n TechVidvan Tutorial: C++ Vectors!<\/p>\n Vector elements are: 6 6 6 6 Vector 1-> 2 3<\/p>\n Vector 2-> 5 7 Vector 1-> 5 7<\/p>\n Vector 2-> 2 3<\/p>\n<\/div>\n Mainly used to access the elements which are stored in a vector. Below are the common iterators:-<\/p>\n Example:-<\/strong><\/p>\n Output:-<\/strong><\/p>\n Helps you in determining the capacity of a vector.<\/p>\n Example:-<\/strong><\/p>\n Output:-<\/strong><\/p>\n Example:-<\/strong><\/p>\n Output:-<\/strong><\/p>\n In this tutorial, we discussed the vectors in C++ and how to initialize them. We also discussed the difference between arrays and vectors. Then we saw about the member functions of vectors in C++ and when you should use a vector in C++.<\/p>\n","protected":false},"excerpt":{"rendered":" As we know that the C++ programming language offers various useful features and functionalities to the programmers. In C++, Vectors are one of the important and exciting features. You can say that vectors are...<\/p>\n","protected":false},"author":1,"featured_media":84637,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3405],"tags":[4219,4220,4221,4222],"class_list":["post-84206","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cpp","tag-capacity-in-c","tag-iterators-in-c","tag-modifiers-in-c","tag-vectors-in-c"],"yoast_head":"\nvector <data-type> variable_name (items)\n<\/pre>\n
How the vectors are stored in C++<\/h3>\n
#include <vector>\nint main()\n{\n std::vector<int> v1;\n}\n<\/pre>\nMember functions of vectors in C++<\/h3>\n
\n
Modifiers in C++<\/h4>\n
\n
#include <bits\/stdc++.h>\n#include <vector>\nusing namespace std;\n \nint main()\n{\n vector<int> v1;\n \n v1.assign(4, 6);\n cout << \"TechVidvan Tutorial: C++ Vectors!\\n\\n\";\n \n cout << \"Vector elements are: \";\n for (int i = 0; i < 4; i++)\n \tcout << v1[i] << \" \";\n\n v1.push_back(15);\n int s = v1.size();\n cout << \"\\nLast element is: \" << v1[s - 1];\n \n cout << \"\\nVector elements after push back are: \";\n for (int i = 0; i < v1.size(); i++)\n cout << v1[i] << \" \";\n \n v1.pop_back();\n\n cout << \"\\nVector elements after pop_back are: \";\n for (int i = 0; i < v1.size(); i++)\n \tcout << v1[i] << \" \";\n v1.insert(v1.begin(), 11);\n \n cout << \"\\nFirst element after insertion is: \" << v1[0];\n v1.erase(v1.begin());\n \n cout << \"\\nFirst element after erasing is: \" << v1[0];\n \n v1.emplace(v1.begin(), 7);\n cout << \"\\nFirst element emplace is: \" << v1[0];\n \n v1.emplace_back(13);\n s = v1.size();\n cout << \"\\nLast element after emplace_back: \" << v1[s - 1];\n \n v1.clear();\n cout << \"\\nVector size after clear is: \" << v1.size();\n \n \n vector<int> o1, o2;\n o1.push_back(2);\n o1.push_back(3);\n o2.push_back(5);\n o2.push_back(7);\n\n cout << \"\\nBefore Swapping\";\n cout << \"\\n\\nVector 1-> \";\n for (int i = 0; i < o1.size(); i++)\n \tcout << o1[i] << \" \";\n \n cout << \"\\n\\nVector 2-> \";\n for (int i = 0; i < o2.size(); i++)\n \tcout << o2[i] << \" \";\n\n o1.swap(o2);\n \n cout << \"\\nAfter Swapping \\n\\nVector 1-> \";\n for (int i = 0; i < o1.size(); i++)\n \tcout << o1[i] << \" \";\n \n cout << \"\\n\\nVector 2-> \";\n for (int i = 0; i < o2.size(); i++)\n \tcout << o2[i] << \" \";\n}\n<\/pre>\n
\nLast element is: 15
\nVector elements after push back are: 6 6 6 6 15
\nVector elements after pop_back are: 6 6 6 6
\nFirst element after insertion is: 11
\nFirst element after erasing is: 6
\nFirst element emplace is: 7
\nLast element after emplace_back: 13
\nVector size after clear is: 0
\nBefore Swapping<\/p>\n
\nAfter Swapping<\/p>\nIterators in C++<\/h4>\n
\n
#include <iostream>\n#include <vector>\n \nusing namespace std;\n \nint main()\n{\n vector<int> v1;\n \n for (int i = 2; i <= 8; i++)\n \tv1.push_back(i);\n \n cout << \"TechVidvan Tutorial: C++ Vectors\" << endl;\n cout << \"Elements are:\" << endl;\n for (auto i = v1.begin(); i != v1.end(); ++i)\n \tcout << *i << \" \";\n \n return 0;\n}\n<\/pre>\n
\nElements are:
\n2 3 4 5 6 7 8<\/div>\nCapacity in C++<\/h4>\n
\n
#include <iostream>\n#include <vector>\n \nusing namespace std;\n \nint main()\n{\n vector<int> v1;\n \n for (int i = 5; i <= 15; i++)\n \tv1.push_back(i);\n \n cout << \"Size of the vector-> \" << v1.size();\n cout << \"\\nCapacity of the vector-> \" << v1.capacity();\n cout << \"\\nMax Size of the vector-> \" << v1.max_size();\n \n v1.resize(5);\n cout << \"\\nSize of the vector after resizing-> \" << v1.size();\n \n if (v1.empty() == false)\n \tcout << \"\\nThe Vector is not empty\";\n else\n \tcout << \"\\nThe Vector is empty\";\n \n return 0;\n}\n<\/pre>\n
\nCapacity of the vector-> 16
\nMax Size of the vector-> 2305843009213693951
\nSize of the vector after resizing-> 5
\nThe Vector is not empty<\/div>\nElement access in C++<\/h4>\n
\n
#include <bits\/stdc++.h>\nusing namespace std;\nint main()\n{\n vector<int> v1;\n \n for (int i = 2; i <= 7; i++)\n \tv1.push_back(i * 4);\n \n cout << \"\\nReference operator[pos]: v1[2]-> \" << v1[2];\n \n cout << \"\\nat: v1.at(3)-> \" << v1.at(3);\n \n cout << \"\\nfront(): v1.front()-> \" << v1.front();\n \n cout << \"\\nback(): v1.back()-> \" << v1.back();\n\n int* data = v1.data();\n \n cout << \"\\nThe first element is-> \" << *data;\n return 0;\n}\n<\/pre>\n
\nat: v1.at(3)-> 20
\nfront(): v1.front()-> 8
\nback(): v1.back()-> 28
\nThe first element is-> 8<\/div>\nSummary<\/h3>\n