swift學習之String常見操作
1.字符拆分(separate)
)
let currentVersion = "V1.0.6.1221" // 定義一段字符串
let strArray = currentVersion.components(separatedBy: ".") // 將字符串分離,分離點是字符串“.”
print("分離的字符:\(strArray)")
運行結果:
分離的字符:["V1", "0", "6", "1221"]
2.增加字符串內容(append)
currentVersion.append(".8086") // 增加字符串內容
print("增加內容後的字符串:\(currentVersion)")
增加內容後的字符串:V1.0.6.1221.8086
3.截取字符串內容(substring)
let cutoutString = (currentVersion as NSString).substring(with: NSRange(location: 0, length: 6)) //截取currentVersion前6位字符串
print("截取的字符串:\(cutoutString)")
運行結果:
截取的字符串:V1.0.6
4.字符串前後綴判斷
// 字符串前綴和後綴判斷
let httpString = "http://www.apple.com"
let jpgName = "Jobs.jpg"
if httpString.hasPrefix("http://") {
print("這是一個網址")
}
if jpgName.hasSuffix(".jpg") {
print("這是一張jpg圖片")
}
這是一個網址
這是一張jpg圖片
5.數字字符串比較大小
// 數字字符串比較大小
let numberStringOne = "123"
let numberStringTwo = "456"
if numberStringOne > numberStringTwo {
print("\(numberStringOne)大於\(numberStringTwo)!")
} else if numberStringOne < numberStringTwo{
print("\(numberStringOne)小於\(numberStringTwo)!")
} else {
print("\(numberStringOne)等於\(numberStringTwo)!")
}
運行結果:
123小於456!
6.數字字符串轉成整型
// 數字字符串轉成整型
let numberStringThree = "1234"
let number = (numberStringThree as NSString).intValue
print("String轉化Int結果:", number)
String轉化Int結果: 1234
通過設置斷點,可以看出,number的類型確實轉成了Int32,如圖: