Swift String 扩展函数.swift

extension String {
    
    // 移除空白
    func removingWhitespace() -> String {
        let whitespacePattern = "\\s+"
        let regex = try? NSRegularExpression(pattern: whitespacePattern, options: .caseInsensitive)
        let range = NSRange(location: 0, length: count)
        return regex?.stringByReplacingMatches(in: self, options: [], range: range, withTemplate: "") ?? self
    }

    // 移除emoji
    func removingEmojis() -> String {
        let emojiPattern = "[\\u{1F600}-\\u{1F64F}\\u{1F300}-\\u{1F5FF}\\u{1F680}-\\u{1F6FF}\\u{1F1E0}-\\u{1F1FF}\\u{2600}-\\u{26FF}\\u{2700}-\\u{27BF}\\u{1F900}-\\u{1F9FF}\\u{1F018}\\u{1F3F0}\\u{1F3FB}-\\u{1F3FF}\\u{1F9B0}-\\u{1F9B3}\\u{1F9E6}]"
        let regex = try? NSRegularExpression(pattern: emojiPattern, options: .caseInsensitive)
        let range = NSRange(location: 0, length: count)
        return regex?.stringByReplacingMatches(in: self, options: [], range: range, withTemplate: "") ?? self
    }
    
    /// 计算字节数，中文算非ASCII字符，占2个字节
    func lengthInBytes() -> Int {
        var length = 0
        for char in self {
            if char.isASCII {
                length += 1
            } else {
                length += 2
            }
        }
        return length
    }
}