Swift中如何汇总对象数组内成员的总分？

我有如下[UserModal]类型的数组：

var data: [UserModal] = [
    UserModal(unit: "Unit 1", data: [
        ScoreModal(name: "Ney", score: 10 ),
        ScoreModal(name: "Mes", score: 20 ),
        ScoreModal(name: "Ro", score: 30 ),
        ScoreModal(name: "Su", score: 40 ),
    ]),
    UserModal(unit: "Unit 2", data: [
        ScoreModal(name: "Ney", score: 10 ),
        ScoreModal(name: "Mes", score: 20 ),
        ScoreModal(name: "Ro", score: 30 ),
        ScoreModal(name: "Su", score: 40 ),
    ]),
    UserModal(unit: "Unit 3", data: [
        ScoreModal(name: "Ney", score: 10 ),
        ScoreModal(name: "Mes", score: 20 ),
        ScoreModal(name: "Ro", score: 30 ),
        ScoreModal(name: "Su", score: 40 ),
    ]),
]

希望计算各成员的总分，得到如下结果：

var result: [ScoreModal] = [
    ScoreModal(name: "Ney", score: 30 ),
    ScoreModal(name: "Mes", score: 60 ),
    ScoreModal(name: "Ro", score: 90 ),
    ScoreModal(name: "Su", score: 120 ),
]

尝试用map操作未成功，求解决方案。

map是一对一的转换操作，无法直接完成聚合求和的需求。你需要通过扁平化数组→分组→求和的步骤实现：

步骤说明 #

1. 扁平化数组：将所有UserModal中的data数组合并为一维数组
2. 按姓名分组：以name为键，将相同姓名的ScoreModal归类到同一组
3. 计算总分：对每组的score累加求和，生成新的ScoreModal实例

完整代码 #

// 先定义Modal结构（若未提前定义）
struct ScoreModal {
    let name: String
    let score: Int
}

struct UserModal {
    let unit: String
    let data: [ScoreModal]
}

// 核心处理逻辑
let flattenedScores = data.flatMap { $0.data }
let groupedByName = Dictionary(grouping: flattenedScores, by: { $0.name })
let result = groupedByName.map { name, scores in
    ScoreModal(name: name, score: scores.reduce(0) { $0 + $1.score })
}.sorted { $0.name < $1.name } // 可选：按姓名排序，确保结果顺序与示例一致

代码解释 #

• flatMap：展开嵌套数组，把每个UserModal的data数组合并成一个包含所有ScoreModal的一维数组
• Dictionary(grouping:by:)：将扁平化后的数组按name分组，得到[String: [ScoreModal]]类型的字典
• reduce：对每组内的score进行累加，计算出每个成员的总分
• sorted：可选操作，用于保证结果的姓名顺序和示例一致，无需特定顺序可省略

内容的提问来源于stack exchange，提问作者Effect