判断银行卡号是否正确

不念不忘少年蓝@ 2022-07-14 01:53 222阅读 0赞

public class func checkCard(number: String) -> Bool {
            var oddSum = 0
            var evenSum = 0
            var allSum = 0
            let cardNumberLength = number.lengthOfBytes(using: String.Encoding.utf8)
            let lastIndex = number.index(number.endIndex, offsetBy: -1)
            let lastNum = Int(number.substring(from: lastIndex))!
            let num = number.substring(to: lastIndex)
            
            for i in (1...cardNumberLength-1).reversed() {
                let start = num.index(num.startIndex, offsetBy: i-1)
                let end = num.index(num.startIndex, offsetBy: i)
                var tempNumber = Int(num.substring(with: start..<end))!
                if cardNumberLength % 2 == 1 {
                    if (i % 2 == 0) {
                        tempNumber *= 2
                        if tempNumber >= 10 {
                            tempNumber -= 9
                        }
                        evenSum += tempNumber
                    }else {
                        oddSum += tempNumber
                    }
                }else {
                    if (i % 2 == 1) {
                        tempNumber *= 2
                        if tempNumber >= 10 {
                            tempNumber -= 9
                        }
                        evenSum += tempNumber
                    }else {
                        oddSum += tempNumber
                    }
                }
            }
            
            allSum = oddSum + evenSum
            allSum += lastNum
            if allSum % 10 == 0 {
                return true
            }
            return false
        }

**测试了农行和招商银行的银行卡，是可以通过的。**