Swift 字符
2021-03-30 本文已影响0人
西风那个吹呀吹
- 字符是否是ASCII码值
/// A Boolean value indicating whether this is an ASCII character.
@inlinable public var isASCII: Bool { get }
- ASCII码值
@inlinable public var asciiValue: UInt8? { get }
- 字符是否是空格
/// A Boolean value indicating whether this character represents whitespace,
/// including newlines.
///
/// For example, the following characters all represent whitespace:
///
/// - "\t" (U+0009 CHARACTER TABULATION) 制表符
/// - " " (U+0020 SPACE) 空格
/// - U+2029 PARAGRAPH SEPARATOR 段落分隔符
/// - U+3000 IDEOGRAPHIC SPACE 表意空格
public var isWhitespace: Bool { get }
- 字符是否是换行符
/// A Boolean value indicating whether this character represents a newline.
///
/// For example, the following characters all represent newlines:
///
/// - "\n" (U+000A): LINE FEED (LF)
/// - U+000B: LINE TABULATION (VT)
/// - U+000C: FORM FEED (FF)
/// - "\r" (U+000D): CARRIAGE RETURN (CR)
/// - "\r\n" (U+000D U+000A): CR-LF
/// - U+0085: NEXT LINE (NEL)
/// - U+2028: LINE SEPARATOR
/// - U+2029: PARAGRAPH SEPARATOR
@inlinable public var isNewline: Bool { get }
- 字符是否是数字
/// A Boolean value indicating whether this character represents a number.
///
/// For example, the following characters all represent numbers:
///
/// - "7" (U+0037 DIGIT SEVEN)
/// - "⅚" (U+215A VULGAR FRACTION FIVE SIXTHS)
/// - "㊈" (U+3288 CIRCLED IDEOGRAPH NINE)
/// - "𝟠" (U+1D7E0 MATHEMATICAL DOUBLE-STRUCK DIGIT EIGHT)
/// - "๒" (U+0E52 THAI DIGIT TWO)
public var isNumber: Bool { get }
- 字符是否是整数
/// A Boolean value indicating whether this character represents a whole
/// number.
///
/// For example, the following characters all represent whole numbers:
///
/// - "1" (U+0031 DIGIT ONE) => 1
/// - "५" (U+096B DEVANAGARI DIGIT FIVE) => 5
/// - "๙" (U+0E59 THAI DIGIT NINE) => 9
/// - "万" (U+4E07 CJK UNIFIED IDEOGRAPH-4E07) => 10_000
@inlinable public var isWholeNumber: Bool { get }
- isNumber与isWholeNumber的区别
let number: Character = "⅚";
print(number.isNumber) // 打印结果： true
print(number.isWholeNumber) // 打印结果： false
- 字符转整数
/// The numeric value this character represents, if it represents a whole
/// number.
///
/// If this character does not represent a whole number, or the value is too
/// large to represent as an `Int`, the value of this property is `nil`.
///
/// let chars: [Character] = ["4", "④", "万", "a"]
/// for ch in chars {
/// print(ch, "-->", ch.wholeNumberValue)
/// }
/// // 4 --> 4
/// // ④ --> 4
/// // 万 --> 10000
/// // a --> nil
public var wholeNumberValue: Int? { get }
- 字符是否是十六进制数字
/// A Boolean value indicating whether this character represents a
/// hexadecimal digit.
///
/// Hexadecimal digits include 0-9, Latin letters a-f and A-F, and their
/// fullwidth compatibility forms. To get the character's value, use the
/// `hexDigitValue` property.
@inlinable public var isHexDigit: Bool { get }
- 字符转十六进制数字
/// The numeric value this character represents, if it is a hexadecimal digit.
///
/// Hexadecimal digits include 0-9, Latin letters a-f and A-F, and their
/// fullwidth compatibility forms. If the character does not represent a
/// hexadecimal digit, the value of this property is `nil`.
///
/// let chars: [Character] = ["1", "a", "Ｆ", "g"]
/// for ch in chars {
/// print(ch, "-->", ch.hexDigitValue)
/// }
/// // 1 --> 1
/// // a --> 10
/// // Ｆ --> 15
/// // g --> nil
public var hexDigitValue: Int? { get }
- 字符是否为字母
/// A Boolean value indicating whether this character is a letter.
///
/// For example, the following characters are all letters:
///
/// - "A" (U+0041 LATIN CAPITAL LETTER A)
/// - "é" (U+0065 LATIN SMALL LETTER E, U+0301 COMBINING ACUTE ACCENT)
/// - "ϴ" (U+03F4 GREEK CAPITAL THETA SYMBOL)
/// - "ڈ" (U+0688 ARABIC LETTER DDAL)
/// - "日" (U+65E5 CJK UNIFIED IDEOGRAPH-65E5)
/// - "ᚨ" (U+16A8 RUNIC LETTER ANSUZ A)
public var isLetter: Bool { get }
- 返回字符的大写版本，返回值为字符串
/// Returns an uppercased version of this character.
///
/// Because case conversion can result in multiple characters, the result
/// of `uppercased()` is a string.
///
/// let chars: [Character] = ["e", "é", "и", "π", "ß", "1"]
/// for ch in chars {
/// print(ch, "-->", ch.uppercased())
/// }
/// // e --> E
/// // é --> É
/// // и --> И
/// // π --> Π
/// // ß --> SS
/// // 1 --> 1
public func uppercased() -> String
- 返回字符的小写版，返回值为字符串
/// Returns a lowercased version of this character.
///
/// Because case conversion can result in multiple characters, the result
/// of `lowercased()` is a string.
///
/// let chars: [Character] = ["E", "É", "И", "Π", "1"]
/// for ch in chars {
/// print(ch, "-->", ch.lowercased())
/// }
/// // E --> e
/// // É --> é
/// // И --> и
/// // Π --> π
/// // 1 --> 1
public func lowercased() -> String
- 字符是否为大写
/// A Boolean value indicating whether this character is considered uppercase.
///
/// Uppercase characters vary under case-conversion to lowercase, but not when
/// converted to uppercase. The following characters are all uppercase:
///
/// - "É" (U+0045 LATIN CAPITAL LETTER E, U+0301 COMBINING ACUTE ACCENT)
/// - "И" (U+0418 CYRILLIC CAPITAL LETTER I)
/// - "Π" (U+03A0 GREEK CAPITAL LETTER PI)
@inlinable public var isUppercase: Bool { get }
- 字符是否为小写
/// A Boolean value indicating whether this character is considered lowercase.
///
/// Lowercase characters change when converted to uppercase, but not when
/// converted to lowercase. The following characters are all lowercase:
///
/// - "é" (U+0065 LATIN SMALL LETTER E, U+0301 COMBINING ACUTE ACCENT)
/// - "и" (U+0438 CYRILLIC SMALL LETTER I)
/// - "π" (U+03C0 GREEK SMALL LETTER PI)
@inlinable public var isLowercase: Bool { get }
- 字符是否是以任何形式改变
/// A Boolean value indicating whether this character changes under any form
/// of case conversion.
@inlinable public var isCased: Bool { get }
- 字符是否符号
/// A Boolean value indicating whether this character represents a symbol.
///
/// This property is `true` only for characters composed of scalars in the
/// "Math_Symbol", "Currency_Symbol", "Modifier_Symbol", or "Other_Symbol"
/// categories in the
/// [Unicode Standard](https://unicode.org/reports/tr44/#General_Category_Values).
///
/// For example, the following characters all represent symbols:
///
/// - "®" (U+00AE REGISTERED SIGN)
/// - "⌹" (U+2339 APL FUNCTIONAL SYMBOL QUAD DIVIDE)
/// - "⡆" (U+2846 BRAILLE PATTERN DOTS-237)
public var isSymbol: Bool { get }
- 字符是否是数学符号
/// A Boolean value indicating whether this character represents a symbol
/// that naturally appears in mathematical contexts.
///
/// For example, the following characters all represent math symbols:
///
/// - "+" (U+002B PLUS SIGN)
/// - "∫" (U+222B INTEGRAL)
/// - "ϰ" (U+03F0 GREEK KAPPA SYMBOL)
///
/// The set of characters that have an `isMathSymbol` value of `true` is not
/// a strict subset of those for which `isSymbol` is `true`. This includes
/// characters used both as letters and commonly in mathematical formulas.
/// For example, "ϰ" (U+03F0 GREEK KAPPA SYMBOL) is considered both a
/// mathematical symbol and a letter.
///
/// This property corresponds to the "Math" property in the
/// [Unicode Standard](http://www.unicode.org/versions/latest/).
public var isMathSymbol: Bool { get }
- 字符是否表示货币符号
/// A Boolean value indicating whether this character represents a currency
/// symbol.
///
/// For example, the following characters all represent currency symbols:
///
/// - "$" (U+0024 DOLLAR SIGN)
/// - "¥" (U+00A5 YEN SIGN)
/// - "€" (U+20AC EURO SIGN)
public var isCurrencySymbol: Bool { get }
- 字符是否表示标点符号
/// A Boolean value indicating whether this character represents punctuation.
///
/// For example, the following characters all represent punctuation:
///
/// - "!" (U+0021 EXCLAMATION MARK)
/// - "؟" (U+061F ARABIC QUESTION MARK)
/// - "…" (U+2026 HORIZONTAL ELLIPSIS)
/// - "—" (U+2014 EM DASH)
/// - "“" (U+201C LEFT DOUBLE QUOTATION MARK)
public var isPunctuation: Bool { get }
-
...方法，返回包含两个边界的闭合范围
/// Returns a closed range that contains both of its bounds.
///
/// Use the closed range operator (`...`) to create a closed range of any type
/// that conforms to the `Comparable` protocol. This example creates a
/// `ClosedRange<Character>` from "a" up to, and including, "z".
///
/// let lowercase = "a"..."z"
/// print(lowercase.contains("z"))
/// // Prints "true"
///
/// - Parameters:
/// - minimum: The lower bound for the range.
/// - maximum: The upper bound for the range.
public static func ... (minimum: Character, maximum: Character) -> ClosedRange<Character>
-
..<方法，左边界到右边界的区间，值不包括右边界值
/// Returns a half-open range that contains its lower bound but not its upper
/// bound.
///
/// Use the half-open range operator (`..<`) to create a range of any type
/// that conforms to the `Comparable` protocol. This example creates a
/// `Range<Double>` from zero up to, but not including, 5.0.
///
/// let lessThanFive = 0.0..<5.0
/// print(lessThanFive.contains(3.14)) // Prints "true"
/// print(lessThanFive.contains(5.0)) // Prints "false"
///
/// - Parameters:
/// - minimum: The lower bound for the range.
/// - maximum: The upper bound for the range.
public static func ..< (minimum: Character, maximum: Character) -> Range<Character>
- prefix
..<方法，返回最大但不包括其上限的部分范围
/// Returns a partial range up to, but not including, its upper bound.
///
/// Use the prefix half-open range operator (prefix `..<`) to create a
/// partial range of any type that conforms to the `Comparable` protocol.
/// This example creates a `PartialRangeUpTo<Double>` instance that includes
/// any value less than `5.0`.
///
/// let upToFive = ..<5.0
///
/// upToFive.contains(3.14) // true
/// upToFive.contains(6.28) // false
/// upToFive.contains(5.0) // false
///
/// You can use this type of partial range of a collection's indices to
/// represent the range from the start of the collection up to, but not
/// including, the partial range's upper bound.
///
/// let numbers = [10, 20, 30, 40, 50, 60, 70]
/// print(numbers[..<3])
/// // Prints "[10, 20, 30]"
///
/// - Parameter maximum: The upper bound for the range.
prefix public static func ..< (maximum: Character) -> PartialRangeUpTo<Character>
- prefix
...方法，返回部分范围（包括上限）
/// Returns a partial range up to, and including, its upper bound.
///
/// Use the prefix closed range operator (prefix `...`) to create a partial
/// range of any type that conforms to the `Comparable` protocol. This
/// example creates a `PartialRangeThrough<Double>` instance that includes
/// any value less than or equal to `5.0`.
///
/// let throughFive = ...5.0
///
/// throughFive.contains(4.0) // true
/// throughFive.contains(5.0) // true
/// throughFive.contains(6.0) // false
///
/// You can use this type of partial range of a collection's indices to
/// represent the range from the start of the collection up to, and
/// including, the partial range's upper bound.
///
/// let numbers = [10, 20, 30, 40, 50, 60, 70]
/// print(numbers[...3])
/// // Prints "[10, 20, 30, 40]"
///
/// - Parameter maximum: The upper bound for the range.
prefix public static func ... (maximum: Character) -> PartialRangeThrough<Character>
- postfix
...方法，返回部分范围，包括下限
/// Returns a partial range extending upward from a lower bound.
///
/// Use the postfix range operator (postfix `...`) to create a partial range
/// of any type that conforms to the `Comparable` protocol. This example
/// creates a `PartialRangeFrom<Double>` instance that includes any value
/// greater than or equal to `5.0`.
///
/// let atLeastFive = 5.0...
///
/// atLeastFive.contains(4.0) // false
/// atLeastFive.contains(5.0) // true
/// atLeastFive.contains(6.0) // true
///
/// You can use this type of partial range of a collection's indices to
/// represent the range from the partial range's lower bound up to the end
/// of the collection.
///
/// let numbers = [10, 20, 30, 40, 50, 60, 70]
/// print(numbers[3...])
/// // Prints "[40, 50, 60, 70]"
///
/// - Parameter minimum: The lower bound for the range.
postfix public static func ... (minimum: Character) -> PartialRangeFrom<Character>
-
><=>=!=方法
@inlinable public static func > (lhs: Character, rhs: Character) -> Bool
@inlinable public static func <= (lhs: Character, rhs: Character) -> Bool
@inlinable public static func >= (lhs: Character, rhs: Character) -> Bool
public static func != (lhs: Character, rhs: Character) -> Bool
