Swift数组元素替换需求：通过for循环替换指定字符串元素

Hey there! Let's get your array replacement logic sorted out. The code you have right now has a couple of issues that are keeping it from working as expected:

• self.etype.contains("VALUE ACTIVITY") checks if the entire array has that string, not if the current item in the loop is that string.
• index(of: "VALUE ACTIVITY") only returns the first occurrence's index, so you can't use it to replace every matching element in the loop.

Option 1: Fix the Existing For Loop #

If you want to stick with a for loop to modify the original array in place, here's how to adjust it:

for i in 0..<self.etype.count {
    let currentItem = self.etype[i]
    switch currentItem {
    case "VALUE ACTIVITY":
        self.etype[i] = "Value"
    case "BONUS ACTIVITY":
        self.etype[i] = "Bonus"
    case "JACKPOT EVENTS":
        self.etype[i] = "Jackpot"
    default:
        // Leave other items unchanged if needed
        break
    }
}

This loop goes through each index, checks the value at that position, and replaces it with the corresponding shortened string directly in the original array.

Option 2: Use Swift's map (More Idiomatic Approach) #

Swift encourages using functional methods like map for this kind of transformation—it's cleaner and avoids manual index management. You can create a new array with the replaced values (and assign it back to etype):

self.etype = self.etype.map { item in
    switch item {
    case "VALUE ACTIVITY":
        return "Value"
    case "BONUS ACTIVITY":
        return "Bonus"
    case "JACKPOT EVENTS":
        return "Jackpot"
    default:
        return item
    }
}

Bonus: Use a Replacement Dictionary for Scalability #

If you ever need to add more replacement rules later, using a dictionary to store the mappings makes your code easier to maintain:

// Define your replacement rules in one place
let replacementRules: [String: String] = [
    "VALUE ACTIVITY": "Value",
    "BONUS ACTIVITY": "Bonus",
    "JACKPOT EVENTS": "Jackpot"
]

// Apply the replacements with map
self.etype = self.etype.map { replacementRules[$0] ?? $0 }

The ?? $0 means "if there's no matching rule for the item, just keep the original value".

内容的提问来源于stack exchange，提问作者gaus