swiftPractice[24]_迴圈練習（上）

nested loop 巢狀迴圈練習

消失這麼久就是卡在迴圈裡出不來了，難得完成一部分趕快上岸！😅

簡易練習項目：

1. 從 segmented control 選擇形狀，有正方形，三角形，金字塔和菱形四種
2. 從 slider 改變數量

IBOutlet & IBAction

 @IBOutlet weak var shapeSegments: UISegmentedControl!
 @IBOutlet weak var textLabel: UILabel!
 @IBOutlet weak var slider: UISlider!
 @IBOutlet weak var countLabel: UILabel!

正方形

裡面的迴圈控制同一排的數量；外面控制有幾排

    func squareLoop(){
        icon = ""
        for _ in 1...count{
            for _ in 1...count{
                icon += "🌕"
            } 
            //控制換行
            icon += "\n"
        }
        textLabel.text = icon
    }

三角形

每一排icon的個數遞增，數量剛好等於外層控制牌數迴圈的 i

 func triangleLoop(){
        icon = ""
        for i in 1...count{
            for _ in 1...i{
                icon += "🌺"
            }
            icon += "\n"
        }
        textLabel.text = icon
    }

金字塔

金字塔本身用月亮🌕顯示，外圍用酪梨🥑，先分別建立各自的變數，然後在迴圈裡控制數量增減。

    func pyramid(){
        icon = ""
        var moon = 1
        var avocado = count - 1
        //外層控制行數，行數等於count個數
        for i in 1...count{
            for _ in 0..<avocado{
                icon += "🥑"
            }
            for _ in 1...moon{
                icon += "🌕"
            }
            //每換一行，酪梨少一個、月亮多兩個
            avocado -= 1
            moon += 2
            icon += "\n"
        }
        textLabel.text = icon
    }

菱形

跟金字塔的概念類似，但過了中線後圖案記數的方式會改變

    func diamond(){
        icon = ""     
        let totalLines = count*2-1//總行數
        var flowerCount = 1 //菱形
        var moonCount = count - 1 //外圍
        
        for i in 1...totalLines{
            for _ in 0..<moonCount{
                icon += "🌕"
            }
            for _ in 1...flowerCount{
                icon += "🌺"
            }
          //中線之前
          if i < count{
                flowerCount += 2
                moonCount -= 1
            //中線之後
            }else{
                flowerCount -= 2
                moonCount += 1
            }
            icon += "\n"
        }
        textLabel.text = icon
    }

完整程式碼

import UIKit

class ViewController: UIViewController {
    var icon = ""
    var count = 1
    @IBOutlet weak var shapeSegments: UISegmentedControl!
    @IBOutlet weak var textLabel: UILabel!
    @IBOutlet weak var slider: UISlider!
    @IBOutlet weak var countLabel: UILabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        countLabel.text = "1"
    }
    
    func squareLoop(){
        icon = ""
        for _ in 1...count{
            for _ in 1...count{
                icon += "🌕"
            }
            icon += "\n"
        }
        textLabel.text = icon
    }
    
    func triangleLoop(){
        icon = ""
        for i in 1...count{
            for _ in 1...i{
                icon += "🌺"
            }
            icon += "\n"
        }
        textLabel.text = icon
    }
    
    func pyramid(){
        icon = ""
        var moon = 1
        var avocado = count - 1
        for i in 1...count{
            for _ in 0..<avocado{
                icon += "🥑"
            }
            for _ in 1...moon{
                icon += "🌕"
            }
            avocado -= 1
            moon += 2
            icon += "\n"
        }
        textLabel.text = icon
    }
    
    func diamond(){
        icon = ""
        let totalLines = count*2-1
        var flowerCount = 1 //中間
        var moonCount = count - 1 //旁邊
        
        for i in 1...totalLines{
            for _ in 0..<moonCount{
                icon += "🌕"
            }
            for _ in 1...flowerCount{
                icon += "🌺"
            }
          if i < count{
                flowerCount += 2
                moonCount -= 1
            }else{
                flowerCount -= 2
                moonCount += 1
            }
            icon += "\n"
        }
        textLabel.text = icon
    }
    //控制數量
    @IBAction func adjustNumber(_ sender: UISlider) {
        sender.value = sender.value.rounded()
        count = Int(sender.value)
        countLabel.text = "\(count)"
        
        switch shapeSegments.selectedSegmentIndex{
        case 0:
            squareLoop()
        case 1:
            triangleLoop()
        case 2:
            pyramid()
        default:
            diamond()
        }
    }
    //選擇形狀
    @IBAction func selectSegment(_ sender: UISegmentedControl){
        slider.setValue(0, animated: true)
        countLabel.text = "1"
        textLabel.text = ""
    }
}

後記

為了for in loop 腦袋打結好一陣子，想通之後反而會忘記之前自己為什麼卡這麼久😂進階版本應該很快也可以寫完吧（？

作業出處：

#60 畫星星蘋果

GitHub

GitHub - tania-liu/loopPractice