我们如何使用ForEach在SwiftUI中计算一些数据？

Question

我想知道我们是否可以在ForEach中进行计数或一些数学运算，这是我的代码，我想在完成ForEach循环后获得A和B的计数。有可能吗？

struct ContentView: View {

@State var appData: [String] = ["A", "B", "A", "A", "B"]

var body: some View {

    
    ForEach(appData, id: \.self) { item in

        Text(item)
            .font(.title)
            .bold()
            .foregroundColor(item == "A" ? Color.red : Color.blue)

    }
    
    Text("Count of A: ")
    Text("Count of B: ")
    
    
    
        
    }
}

Answer 1

struct ContentView: View {
    
    @State var appData: [String] = ["A", "B", "A", "A", "B"]
    
    var body: some View {
    
        
        ForEach(appData, id: \.self) { item in
          let Calculation = 1 + 2
          return  Text(item)
                .font(.title)
                .bold()
                .foregroundColor(item == "A" ? Color.red : Color.blue)
    
        }
        
        Text("Count of A: ")
        Text("Count of B: ")
        
        
        
            
        }
    }

Answer 2

您可以在主体外部声明两个计算的属性：

var aCount: Int {
    appData
        .filter { $0 == "A" }
        .count
}

var bCount: Int {
    appData
        .filter { $0 == "B" }
        .count
}

然后。像这样在内部使用它们：

Text("Count of A: \(aCount)")
Text("Count of B: \(bCount)")