std::vector::begin, std::vector::cbegin - cppreference.com

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`iterator begin();`		(fino al c++11)

`iterator begin() noexcept;`		(dal C++11)

`const_iterator begin() const;`		(fino al c++11)

`const_iterator begin() const noexcept;`		(dal C++11)

`const_iterator cbegin() const noexcept;`

Restituisce un iteratore al primo elemento del container.

Se il container è vuoto, l'iteratore restituito sarà uguale a end().

Parametri

(nessuno)

Valore restituito

Iteratore al primo elemento

Complessità

Costante

Example

#include <iostream>
#include <vector>
#include <string>

int main()
{
	std::vector<int> ints {1, 2, 4, 8, 16};
	std::vector<std::string> fruits {"orange", "apple", "raspberry"};
	std::vector<char> empty;

	// Sums all integers in the vector ints (if any), printing only the result.
	int sum = 0;
	for (auto it = ints.cbegin(); it != ints.cend(); it++)
		sum += *it;
	std::cout << "Sum of ints: " << sum << "\n";

	// Prints the first fruit in the vector fruits, without checking if there is one.
	std::cout << "First fruit: " << *fruits.begin() << "\n";

	if (empty.begin() == empty.end())
		std::cout << "vector 'empty' is indeed empty.\n";
}

Output:

Sum of ints: 31
First fruit: orange
vector 'empty' is indeed empty.

Vedi anche


	restituisce un iteratore fino alla fine Original: returns an iterator to the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico) [modifica]