Introduce Parameter Object C语言示例

假设有一个名为“图形”的结构体，该结构体包含三个属性：形状（shape）、半径（radius）和边长（length）。我们现在需要编写一个名为“计算图形面积”的函数，计算图形的面积。使用引入参数对象重构手法，代码如下：

// 原始代码
struct Shape {
    char* shape;
    double radius;
    double length;
};

double calculate_area(struct Shape shape) {
    if (strcmp(shape.shape, "圆") == 0) {
        return 3.14 * shape.radius * shape.radius;
    } else if (strcmp(shape.shape, "正方形") == 0) {
        return shape.length * shape.length;
    } else {
        return 0;
    }
}

// 重构后的代码
struct Shape {
    char* shape;
    double radius;
    double length;
};

double calculate_circle_area(double radius) {
    return 3.14 * radius * radius;
}

double calculate_square_area(double length) {
    return length * length;
}

double calculate_area(struct Shape shape) {
    if (strcmp(shape.shape, "圆") == 0) {
        return calculate_circle_area(shape.radius);
    } else if (strcmp(shape.shape, "正方形") == 0) {
        return calculate_square_area(shape.length);
    } else {
        return 0;
    }
}

int main() {
    struct Shape circle = { "圆", 5, 0 };
    double area = calculate_area(circle);
    printf("圆的面积为