stl vector 函数

C ++ vector :: capacity()函数 (C++ vector::capacity() function)

vector::capacity() is a library function of "vector" header, it is used to find the capacity of a vector, it returns the storage space currently allocated to the vector.

vector :: capacity()是“ vector”头文件的库函数，用于查找向量的容量，它返回当前分配给该向量的存储空间。

Note: To use vector, include <vector> header.

注意：要使用向量，请包含<vector>标头。

Syntax of vector::capacity() function

vector :: capacity()函数的语法

vector::capacity();

Parameter(s): void – It accepts nothing as a parameter.

参数： void –不接受任何参数。

Return value: size_type – It returns capacity i.e. storage space of a vector.

返回值： size_type –返回容量，即向量的存储空间。

Example:

例：

Input:    vector
    
      vector1{ 1, 2, 3, 4, 5 };    Function call:    cout << vector1.capacity();    Output:    8
    

C ++程序演示vector :: capacity()函数的示例 (C++ program to demonstrate example of vector::capacity() function)

//C++ STL program to demonstrate example of//vector::capacity() function#include 
    
     #include 
     
      using namespace std;int main(){
       vector
      
        v1;    //printing the size & capacity of the vector    cout << "Total number of elements: " << v1.size() << endl;    cout << "Storage space: " << v1.capacity() << endl;    //pushing elements    v1.push_back(10);    v1.push_back(20);    v1.push_back(30);    v1.push_back(40);    v1.push_back(50);    //printing the size & capacity of the vector    cout << "Total number of elements: " << v1.size() << endl;    cout << "Storage space: " << v1.capacity() << endl;    return 0;}
      
     
    

Output

输出量

Total number of elements: 0Storage space: 0Total number of elements: 5Storage space: 8

Reference:

参考：

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stl vector 函数