How to define dynamic array

Dynamic array is a data structure that can allocate and release memory space on demand when the program is running. Compared with static arrays, the length of dynamic arrays can be dynamically expanded or reduced, making them more flexible and adaptable to various needs. In many programming languages, dynamic arrays are implemented using heap memory.

In most programming languages, the definition and use of dynamic arrays are similar. The following uses Python and C as examples to introduce the definition and use of dynamic arrays in detail.

Python

In Python, the definition of dynamic array uses the built-in list class. You can directly use [] to create an empty Dynamic array. Dynamic arrays in Python can hold elements of different types, or even elements of different types at the same time.

The following is a sample code to create and use a dynamic array:

# 创建一个空的动态数组
dynamic_array = []

# 添加元素到动态数组
dynamic_array.append(10)
dynamic_array.append("Hello")
dynamic_array.append(3.14)

# 访问和修改动态数组的元素
print(dynamic_array[0])  # 输出: 10
print(dynamic_array[1])  # 输出: Hello

dynamic_array[2] = "World"
print(dynamic_array[2])  # 输出: World

# 删除动态数组的元素
dynamic_array.pop(1)  # 移除索引为1的元素
print(dynamic_array)  # 输出: [10, 3.14]

C

In C, the definition of dynamic arrays relies on pointers and dynamic memory allocation operatorsnew and delete. You can dynamically allocate memory on the heap through the new operator, and then use pointers to operate dynamic arrays.

The following is a sample code that uses C to define and operate dynamic arrays:

#include<iostream>

int main() {
    int* dynamic_array = new int[5];  // 创建一个大小为5的动态数组

    // 添加元素到动态数组
    dynamic_array[0] = 10;
    dynamic_array[1] = 20;
    dynamic_array[2] = 30;
    dynamic_array[3] = 40;
    dynamic_array[4] = 50;

    // 访问和修改动态数组的元素
    std::cout << dynamic_array[0] << std::endl;  // 输出: 10
    std::cout << dynamic_array[1] << std::endl;  // 输出: 20

    dynamic_array[2] = 100;
    std::cout << dynamic_array[2] << std::endl;  // 输出: 100

    // 删除动态数组
    delete[] dynamic_array;

    return 0;
}

The above is the definition and use of dynamic arrays in Python and C, two common programming languages. No matter which programming language you use, mastering the concepts and operations of dynamic arrays can make your program more flexible and efficient. I hope this article can be helpful to readers.

The above is the detailed content of How to define dynamic array. For more information, please follow other related articles on the PHP Chinese website!