如何过滤JSON空值与Nil值？优化可选配料数组构建方案

针对批量过滤20个可选配料字段的需求，无需重复编写20次if let判断，以下是几种简洁的实现方式：

方案一：直接数组收集+过滤（仅配料） #

在meals结构体中添加计算属性，将所有配料字段放入数组后统一处理：

struct meals: Codable {
    // 保留原有所有字段
    
    // 过滤后的非空配料数组
    var filteredIngredients: [String] {
        let allIngredients = [
            strIngredient1, strIngredient2, strIngredient3, strIngredient4, strIngredient5,
            strIngredient6, strIngredient7, strIngredient8, strIngredient9, strIngredient10,
            strIngredient11, strIngredient12, strIngredient13, strIngredient14, strIngredient15,
            strIngredient16, strIngredient17, strIngredient18, strIngredient19, strIngredient20
        ]
        
        // 剔除nil值→修剪空格→过滤空字符串
        return allIngredients
            .compactMap { $0?.trimmingCharacters(in: .whitespacesAndNewlines) }
            .filter { !$0.isEmpty }
    }
}

方案二：配料与对应度量配对过滤 #

如果需要同时保留配料和对应的度量值，用zip将两个数组配对后处理：

struct meals: Codable {
    // 保留原有所有字段
    
    // 过滤后的配料-度量配对数组
    var filteredIngredientMeasures: [(ingredient: String, measure: String)] {
        let allIngredients = [
            strIngredient1, strIngredient2, strIngredient3, strIngredient4, strIngredient5,
            strIngredient6, strIngredient7, strIngredient8, strIngredient9, strIngredient10,
            strIngredient11, strIngredient12, strIngredient13, strIngredient14, strIngredient15,
            strIngredient16, strIngredient17, strIngredient18, strIngredient19, strIngredient20
        ]
        
        let allMeasures = [
            strMeasure1, strMeasure2, strMeasure3, strMeasure4, strMeasure5,
            strMeasure6, strMeasure7, strMeasure8, strMeasure9, strMeasure10,
            strMeasure11, strMeasure12, strMeasure13, strMeasure14, strMeasure15,
            strMeasure16, strMeasure17, strMeasure18, strMeasure19, strMeasure20
        ]
        
        return zip(allIngredients, allMeasures)
            .compactMap { (ingredientOpt, measureOpt) in
                guard let ingredient = ingredientOpt?.trimmingCharacters(in: .whitespacesAndNewlines),
                      !ingredient.isEmpty else {
                    return nil
                }
                let cleanedMeasure = measureOpt?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
                return (ingredient, cleanedMeasure)
            }
    }
}

方案三：Mirror反射（不推荐，仅作扩展） #

若字段数量极多，可通过Mirror反射遍历属性，但该方式性能略差且依赖命名规则，非首选：

struct meals: Codable {
    // 保留原有所有字段
    
    var filteredIngredientsViaMirror: [String] {
        let mirror = Mirror(reflecting: self)
        return mirror.children
            .filter { $0.label?.starts(with: "strIngredient") ?? false }
            .compactMap { $0.value as? String }
            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
            .filter { !$0.isEmpty }
    }
}

注意事项 #

• 优先选择方案一或方案二，代码可读性高、性能稳定，且能精准控制字段顺序
• 加入trimmingCharacters是为了过滤仅含空格的无效字段

内容的提问来源于stack exchange，提问作者Andrew