Is it possible to validate IMEI Number?

Question

For a mobile shop application, I need to validate an IMEI number. I know how to validate based on input length, but is their any other mechanism for validating the input number?

Answer 1

IMEI can start with 0 digit. This is why the function input is string. Thanks for the method @KarlNicol

Golang

func IsValid(imei string) bool {
    digits := strings.Split(imei, "")

    numOfDigits := len(digits)

    if numOfDigits != 15 {
        return false
    }

    checkingDigit, err := strconv.ParseInt(digits[numOfDigits-1], 10, 8)
    if err != nil {
        return false
    }

    checkSum := int64(0)
    for i := 0; i < numOfDigits-1; i++ { // we dont need the last one
        convertedDigit := ""

        if (i+1)%2 == 0 {
            d, err := strconv.ParseInt(digits[i], 10, 8)
            if err != nil {
                return false
            }
            convertedDigit = strconv.FormatInt(2*d, 10)
        } else {
            convertedDigit = digits[i]
        }

        convertedDigits := strings.Split(convertedDigit, "")

        for _, c := range convertedDigits {
            d, err := strconv.ParseInt(c, 10, 8)
            if err != nil {
                return false
            }
            checkSum = checkSum + d
        }

    }

    if (checkSum+checkingDigit)%10 != 0 {
        return false
    }

    return true
}