C++ 中的数组类


C++ 中的数组类足够高效,并且知道其自身的大小。

用于对数组执行操作的函数为

  • size() = 返回数组的大小,即返回数组的元素数。
  • max_size() = 返回数组的最大元素数。
  • get()、at()、运算符 [] = 访问数组元素。
  • front() = 返回数组的第一个元素。
  • back() = 返回数组的最后一个元素。
  • empty() = 如果数组大小为 true,则返回 true,否则返回 false。
  • fill() = 用特定值填充整个数组。
  • swap() = 交换一个数组与另一个数组的元素。

这里有一个示例来实现上述所有操作 −

示例代码

#include<iostream>
#include<array>
using namespace std;

int main() {
   array<int,4>a = {10, 20, 30, 40};
   array<int,4>a1 = {50, 60, 70, 90};
   cout << "The size of array is : ";
   //size of the array using size()
   cout << a.size() << endl;
   //maximum no of elements of the array
   cout << "Maximum elements array can hold is : ";
   cout << a.max_size() << endl;
   // Printing array elements using at()
   cout << "The array elements are (using at()) : ";
   for ( int i=0; i<4; i++)
      cout << a.at(i) << " ";
      cout << endl;
   // Printing array elements using get()
   cout << "The array elements are (using get()) : ";
   cout << get<0>(a) << " " << get<1>(a) << " "<<endl;
   cout << "The array elements are (using operator[]) : ";
   for ( int i=0; i<4; i++)
      cout << a[i] << " ";
      cout << endl;
   // Printing first element of array
   cout << "First element of array is : ";
   cout << a.front() << endl;
   // Printing last element of array
   cout << "Last element of array is : ";
   cout << a.back() << endl;
   cout << "The second array elements before swapping are : ";
   for (int i=0; i<4; i++)
      cout << a1[i] << " ";
      cout << endl;
   // Swapping a1 values with a
   a.swap(a1);
   // Printing 1st and 2nd array after swapping
   cout << "The first array elements after swapping are : ";
   for (int i=0; i<4; i++)
      cout << a[i] << " ";
      cout << endl;
      cout << "The second array elements after swapping are : ";
   for (int i = 0; i<4; i++)
      cout << a1[i] << " ";
      cout << endl;
   // Checking if it is empty
   a1.empty()? cout << "Array is empty":
   cout << "Array is not empty";
   cout << endl;
   // Filling array with 1
   a.fill(1);
   // Displaying array after filling
   cout << "Array content after filling operation is : ";
   for ( int i = 0; i<4; i++)
      cout << a[i] << " ";
      return 0;
}

输出

The size of array is : 4
Maximum elements array can hold is : 4
The array elements are (using at()) : 10 20 30 40
The array elements are (using get()) : 10 20
The array elements are (using operator[]) : 10 20 30 40
First element of array is : 10
Last element of array is : 40
The second array elements before swapping are : 50 60 70 90
The first array elements after swapping are : 50 60 70 90
The second array elements after swapping are : 10 20 30 40
Array is not empty
Array content after filling operation is : 1 1 1 1

更新日期:30-Jul-2019

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