你所寻找的可能是这两个数组的symmetric difference，但是正如评论中所指出的，你的数据结构并不适合这样做，如果你真的想坚持当前的结构，下面这个可能对你有用：

func symmetricDifference(arrays: [[[String: String]]], by key: String) -> [[String: String]] {
    var result = [String: [String: String]?]()
    for array in arrays {
        for element in array {
            guard let keyValue = element[key] else {
                // Ignore elements that do not contain the key, adjust as needed
                continue
            }
            
            // Check if we already saw the value
            if !result.keys.contains(keyValue) {
                // Add the element
                result[keyValue] = element
            } else {
                // We saw this keyValue already, remove the element
                result.updateValue(nil, forKey: keyValue)
            }
        }
    }
    
    // Only return elements where value is not nil
    return result.values.compactMap { $0 }
}

// Usage
symmetricDifference(arrays: [arr1, arr2], by: "title")

通过使用更合适的数据结构，您可以轻松地使用内置的Set运算符：

struct Category: Hashable {
    let title: String
    let icon: String
    
    func hash(into hasher: inout Hasher) {
        hasher.combine(title)
    }
    
    static func ==(lhs: Category, rhs: Category) -> Bool {
        lhs.title == rhs.title
    }
}

let set1 = Set([Category(title: "News", icon: "news_1"), Category(title: "Food", icon: "food_1")])
let set2 = Set([Category(title: "News", icon: "news_2"), Category(title: "Technology", icon: "tech_1"), Category(title: "News", icon: "news_2")])
let result = set1.symmetricDifference(set2)