在访问数组之前，可以使用indices检查数组是否包含索引：

guard myArray.indices.contains(1) else { return }
let value = myArray[1]

Apple文档：indices

你可以通过各种方式来处理它，例如我在下面给你看一些代码片段，看看哪种情况与你的相似。
1.如果你从数组中按索引获取项目，那么你可以避免数组索引超出范围的错误，如：

if yourIndex <= yourArray.endIndex {
    //Then do your desired operation by getting items by your index            
} else {
    //Do not get items by your index because it is out of range. 
    //Do anything else            
}

1.您可以检查数组是否为空，例如：

if yourArray.isEmpty {
    // Don't do any array item get operations because your array is empty           
} else {
    // Your array is not empty
}

1.你可以检查你的数组是否至少有固定数量的元素，比如：

if yourArray.count >= yourDesiredNumberOfElements {
    // Your array have at least your desired number of elements.
} else {
    // Your array does not have your desired number of elements.
    // your array has less elements than you desire.
}

一个好的解决方案是使用一个带有return可选元素的安全下标。

extension Array {
    public subscript(safeIndex index: Int) -> Element? {
        guard index >= startIndex, index < endIndex else {
            return nil
        }

        return self[index]
    }
}

为了检查索引是否超出界限从而不导致应用崩溃并以另一种方式处理这种情况，

if (yourArray.count - 1) >= yourIndex {
   //Not out of bounds, carry on.
} else {
   //This is when your app would crash due to being out of bounds.
}