Java - 正则表达式检查字符串是否包含连续数字以及其他字符

Question

I am looking to write regular expressions to check if a string contains below:

1. It contains continuous digit which ranges from 2 to 5 digits.
2. It contains continuous digit of more than 9 digits.

For example:

1. Hello, my address is 1 MG Road - Returns false
2. Hello, I stay at 100 Feet Road - Returns true
3. Can you call me 9999273732. this is my number - retuns true.
4. My pin code is 313002 - retuns false.

Answer 1

You can use this regex:

^\D*(?:\d{2,5}|\d{9,})\D*$

DEMO

Short explanation (You can also visit the demo to see an explanation):

• ^ : Start anchor
• \D* : Any amount of non digits
• (?: : Start of a non capture group
• \d{2,5} : 2-5 digit s
• | : Alternator
• \d{9,} : 9 or more digits
• ) : End of non capture group
• \D* : Any amount of non digits
• $ : End anchor

If you use any of the methods:

• String.matches()
• Pattern.matches()
• Matcher.matches()

Then you don't have to specify the start and end anchor, ^ and $

Answer 2

    Pattern pattern =
            Pattern.compile("(?<!\\d)(\\d{2,5})(?!\\d)|\\d{9,}"); 
    Matcher matcher =
            pattern.matcher("111lo, I stay at 100 Feet R10034");  // your input here

    while (matcher.find()) {
        System.out.format("I found the text" +
                        " \"%s\" starting at " +
                        "index %d and ending at index %d.%n",
                matcher.group(),
                matcher.start(),
                matcher.end());
    }

Short explanation:

• (?<!\\d) : negative lookbehind that matches with character that isn't a digit
• \\d{2,5} : digits of length 2 to 5
• (?!\\d) : negative lookahead that matches with character that isn't a digit
• | : alternation
• \\d{9,} : matches digits of length 9 or more

Answer 3

You can do something like that.

fun checkDigit(inputValue: String): Boolean {
    var isContinueDigit = false
    var digitSize = 0

    inputValue.forEach {
        if (it.isDigit()) {
            if (isContinueDigit) {
                digitSize++
            } else {
                isContinueDigit = true
                digitSize = 0
                digitSize++
            }
        } else {
            isContinueDigit = false
        }
    }

    val isDigit: ArrayList<Int> = arrayListOf(2, 3, 4, 5, 9)
    return isDigit.contains(digitSize) || isDigit.last() < digitSize
}