vector functions c++ code example

Example 1: std vector include c++

#include <vector>
std::vector<std::string> x;

Example 2: vector in c++

vector<int> g1; 
  
    for (int i = 1; i <= 5; i++) 
        g1.push_back(i); 
  
    cout << "Output of begin and end: "; 
    for (auto i = g1.begin(); i != g1.end(); ++i) 
        cout << *i << " "; 
  
    cout << "\nOutput of cbegin and cend: "; 
    for (auto i = g1.cbegin(); i != g1.cend(); ++i) 
        cout << *i << " "; 
  
    cout << "\nOutput of rbegin and rend: "; 
    for (auto ir = g1.rbegin(); ir != g1.rend(); ++ir) 
        cout << *ir << " ";

Example 3: vector functions c++

/*Member functions*/
                 Iterators
 -----------------------------------------
 begin | Returns an iterator to the beginning
 end   | Returns an iterator to the end
  
                 Capacity
 -----------------------------------------
 empty    | Checks whether the container is empty
 size     | Returns the number of elements
 reserve  | Reserves storage
 capacity | Returns the number of elements that can be held in currently allocated storage
     
              Element access
 -----------------------------------------
 at	     	| Access specified element with bounds checking
 front  	| Access the first element
 back   	| Access the last element
 operator[] | Access specified element
    
                 Modifiers
 -----------------------------------------
 clear        | Clears the contents
 insert       | Inserts elements
 emplace      | Constructs element in-place
 erase        | Erases elements
 push_back    | Adds an element to the end
 emplace_back | Constructs an element in-place at the end  
 pop_back     | Removes the last element        
 resize       | Changes the number of elements stored     
 swap         | Swaps the contents
  
  *Notes*
  - https://en.cppreference.com/w/cpp/container/vector
  - https://www.geeksforgeeks.org/vector-in-cpp-stl/
  - https://www.tutorialspoint.com/cpp_standard_library/vector.htm

Example 4: vector keyword in c++

template < class T, class Alloc = allocator<T> > class vector;

Example 5: vector in c++ class

#include <iostream>
#include <vector>

class Object
{
	public:
		Object()
		{}
		~Object()
		{}
		void AddInt(int num)
		{
			m_VectorOfInts.push_back(num);
		}
		std::vector<int> GetCopyOfVector()
		{
			return m_VectorOfInts;
		}
		void DisplayVectorContents()
		{
			for( unsigned int i = 0; i < m_VectorOfInts.size(); i++ )
			{
				std::cout << "Element[" << i << "] = " << m_VectorOfInts[i] << std::endl;
			}
			std::cout << std::endl;
		}

	private:
		std::vector<int> m_VectorOfInts;
};

int main()
{
	// Create our class an add a few ints
	Object obj;
	obj.AddInt(32);
	obj.AddInt(56);
	obj.AddInt(21);

	// Display the vector contents so far
	obj.DisplayVectorContents();

	// Creates a copy of the classes container you can only really view whats in 
	// the classes vector container. What ever changes you make here wont effect the class.
	std::vector<int> container1 = obj.GetCopyOfVector();
	// These elements wont be added as it's a copy of the container
	container1.push_back(342);
	container1.push_back(64);
	container1.push_back(123);


	// Display the classes container to see show nothing was added.
	obj.DisplayVectorContents();

	return 0;
}