What is the underlying implementation mechanism of arrays?

The underlying implementation mechanism of the array is a continuous memory unit. The first element is stored at the lowest address, and subsequent elements are stored in sequence. Array elements occupy fixed-size memory units, and the addresses of adjacent elements differ by the element size. Practical use of arrays can efficiently store and process large amounts of data, such as storing 100 student grades.

The underlying implementation mechanism of array

Array is the most basic data structure and is widely used in various programming languages. Understanding its underlying implementation mechanism is crucial to a deep understanding of programming principles.

Under the hood, an array usually consists of a contiguous range of memory cells, each cell storing a data element of a specific type. The first element of the array is stored at the lowest address in memory, followed by subsequent elements in sequence.

The following is a simple integer array implemented in C language:

#include <stdio.h>

int main() {
    int arr[5]; // 声明一个长度为 5 的整数数组

    // 为数组元素赋值
    for (int i = 0; i < 5; i++) {
        arr[i] = i + 1;
    }

    // 打印数组元素
    for (int i = 0; i < 5; i++) {
        printf("arr[%d] = %d\n", i, arr[i]);
    }

    return 0;
}

For this array, its underlying memory structure is as follows:

地址  | 值
-------|------
&arr[0] | 1
&arr[1] | 2
&arr[2] | 3
&arr[3] | 4
&arr[4] | 5

Among them, &arr[0] is the starting address of the array. Each array element occupies one memory location, and the memory addresses between adjacent elements differ by the size of one element (usually 4 bytes for integer types).

Practical Case

Consider the following practical case: a program that needs to store the scores of 100 students. We can use an array of length 100 to store these scores.

# 声明一个包含 100 个浮点数的数组
scores = [0.0] * 100

# 为数组元素赋值
for i in range(100):
    scores[i] = float(input("Enter student %d score: " % (i + 1)))

# 计算平均成绩
average_score = sum(scores) / 100

In this case, the underlying implementation mechanism of the array provides a mechanism to access and store data efficiently, allowing us to easily handle a large number of student scores.

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