How do I remove all separator characters from a string in Kotlin?

Question

I am trying to sanitize a QR code output. The value I am trying to send via Retrofit is

010868193700666621762185642311216939172106131020190603

but OKHttp log show

example.com/endpoint/etc/&Qrcode=%1D010868193700666621762185642311216939%1D172106131020190603

When I use this .trim().replace("\u00D", "")

example.com/endpoint/etc/&Qrcode=010868193700666621762185642311216939%1D172106131020190603

How do I remove those unwanted characters?

You can use Kotlin's String.filter Reference : https://stackoverflow.com/questions/58812220/extract-numbers-from-a-string-kotlin — Franz Andel, Jul 03 '20 at 09:17

score 1 · Accepted Answer · answered Jul 03 '20 at 09:38

https://howtodoinjava.com/regex/java-clean-ascii-text-non-printable-chars/ This here solved my problem. I converted it to an extension in Kotlin like this

val String.cleanTextContent: String
    get() {
        // strips off all non-ASCII characters
        var text = this
        text = text.replace("[^\\x00-\\x7F]".toRegex(), "")

        // erases all the ASCII control characters
        text = text.replace("[\\p{Cntrl}&&[^\r\n\t]]".toRegex(), "")

        // removes non-printable characters from Unicode
        text = text.replace("\\p{C}".toRegex(), "")
        return text.trim()
    }

score 0 · Answer 2 · answered Jul 03 '20 at 09:18

0

You can try below to collect only digits from the string.

var result = string.filter { it.isDigit() }

answered Jul 03 '20 at 09:18

Shalu T D

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this example didn't show but my input may contain a-zA-Z+- – LutfiTekin Jul 03 '20 at 09:21
whats about `answer.replace(regex = "[^A-Za-z0-9 ]", "")` – Shalu T D Jul 03 '20 at 09:25
Please let me know what all characters you need to support? – Shalu T D Jul 03 '20 at 09:26
Yes I thought about it and was going for this but, like I said it may contain + - these and I cannot know – LutfiTekin Jul 03 '20 at 09:27
you need to support + and - too rt? – Shalu T D Jul 03 '20 at 09:27
https://howtodoinjava.com/regex/java-clean-ascii-text-non-printable-chars/ I am trying this and seems to be working for me but I should test some more. – LutfiTekin Jul 03 '20 at 09:28
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/217135/discussion-between-shalu-t-d-and-lutfitekin). – Shalu T D Jul 03 '20 at 09:31

How do I remove all separator characters from a string in Kotlin?

2 Answers2