Swift结构体数组多级排序：按地址、物业名、卧室数排序

需求说明 #

需对存储多单元房产信息的Property结构体数组排序，优先级依次为：站点地址（siteAddress）→ 物业名称（propertyName）→ 卧室数量（bedrooms），最终呈现按地址、物业、卧室数层级归类的有序结果。

原始定义与测试数据 #

struct Property: Hashable {
    var propertyName: String = ""
    var unitNumber: Int = 0
    var bedrooms: Double = 0
    var siteAddress: String = ""
}

var properties: Array<Property> = []
properties.append(Property(propertyName: "Tower A", unitNumber: 211, bedrooms: 2.5, siteAddress: "123 Main Street"))
properties.append(Property(propertyName: "Tower A", unitNumber: 508, bedrooms: 1, siteAddress: "413 Another Street"))
properties.append(Property(propertyName: "Tower B", unitNumber: 816, bedrooms: 2.5, siteAddress: "123 Main Street"))
properties.append(Property(propertyName: "Tower A", unitNumber: 923, bedrooms: 1, siteAddress: "123 Main Street"))
properties.append(Property(propertyName: "Tower A", unitNumber: 104, bedrooms: 3, siteAddress: "123 Main Street"))
properties.append(Property(propertyName: "Tower B", unitNumber: 304, bedrooms: 2, siteAddress: "123 Main Street"))
properties.append(Property(propertyName: "Tower B", unitNumber: 222, bedrooms: 1, siteAddress: "413 Another Street"))
properties.append(Property(propertyName: "Tower A", unitNumber: 601, bedrooms: 2, siteAddress: "413 Another Street"))

优化后的排序实现 #

方式一：分层条件判断（可读性强） #

properties = properties.sorted { this, next in
    // 第一优先级：比较站点地址
    if this.siteAddress != next.siteAddress {
        return this.siteAddress < next.siteAddress
    }
    // 第二优先级：地址相同时比较物业名称
    else if this.propertyName != next.propertyName {
        return this.propertyName < next.propertyName
    }
    // 第三优先级：地址和物业都相同时比较卧室数量（升序）
    else {
        return this.bedrooms < next.bedrooms
    }
}

方式二：元组链式比较（简洁高效） #

Swift支持元组按元素顺序依次比较，完全匹配优先级需求，代码更精简：

properties = properties.sorted {
    ($0.siteAddress, $0.propertyName, $0.bedrooms) < ($1.siteAddress, $1.propertyName, $1.bedrooms)
}

排序结果验证 #

排序后的数组按层级展开如下，与期望结果完全一致：

• 123 Main Street
  • Tower A
    • 923, 1br
    • 211, 2.5br
    • 104, 3br
  • Tower B
    • 304, 2br
    • 816, 2.5br
• 413 Another Street
  • Tower A
    • 508, 1br
    • 601, 2br
  • Tower B
    • 222, 1br

内容的提问来源于stack exchange，提问作者SouthernYankee65