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Format number in kotlin with commas

I'm pretty new to kotlin and would like to know how to format a number with commas.
Currently, my textview shows a number without any commas, i.e, 15000.
I want it to show 15,000 instead.
Here's my code that I want to format:
txtTotalActive.text = it.statewise[0].active
"it.statewise[0].active" is an object that shows number but as I said, it shows without any commas.

Solution:
var inoutValue = it.statewise[0].active
val number = java.lang.Double.valueOf(inoutValue)
val dec = DecimalFormat("#,###,###")
val finalOutput = dec.format(number)
txtTotalActive.text = finalOutput

"%,.2f".format(text.toFloat()) <,> = grouping , 2 = precision/number of decimals after "."

Kotlin check for words in string

I have a NSFW class that scans texts like item names and descriptions against a list of known NSFW-words.
That would be the best approach to test a list of strings like
let nsfw = listof(
"badword",
"curseword",
"ass",
... 200+ more
)
against a string like:
This is the text that contains a badword // returns true
Please note that i need to check for full words. not parts of words.
so the sentence:
The grass is grean // returns false
Because grass is not a bad word.
Ive tried something like this but it doesnt check for full words.
val result = nsfw.filter { it in sentence.toLowerCase() }

You may build a regex like
\b(?:word1|word2|word3...)\b
See the regex demo. Then, use it with the Regex.containsMatchIn method:
val nsfw = listOf(
"badword",
"curseword",
"ass"
)
val s1 = "This is the text that contains a badword"
val s2 = "The grass is grean"
val rx = Regex("\\b(?:${nsfw.joinToString(separator="|")})\\b")
println(rx.containsMatchIn(s1)) // => true
println(rx.containsMatchIn(s2)) // => false
See this Kotlin demo.
Here, nsfw.joinToString(separator="|") joins the words with a pipe (the alternation operator) and the "\\b(?:${nsfw.joinToString(separator="|")})\\b" creates the correct regex.
If your words may contain special regex metacharacters, like +, ?, (, ), etc., you need to "preprocess" the nsfw values with the Regex.escape method:
val rx = Regex("\\b(?:${nsfw.map{Regex.escape(it)}.joinToString("|")})\\b")
^^^^^^^^^^^^^^^^^^^^^^
See the Kotlin demo.
AND one more thing: if the keywords may start/end with chars other than letters, digits and underscores, you cannot rely on \b word boundaries. You may
Use whitespace boundaries: val rx = Regex("(?<!\\S)(?:${nsfw.map{Regex.escape(it)}.joinToString("|")})(?!\\S)")
Use unambiguous word boundaries: val rx = Regex("(?<!\\w)(?:${nsfw.map{Regex.escape(it)}.joinToString("|")})(?!\\w)")

You can use split() on the string that you want to check, with space as a delimiter, so you create a list of its words, although this does not always guarantee that all words will be extracted successfully, since there could exist other word separators like dots or commas etc. If that suits you, do this:
val nsfw = listOf(
"badword",
"curseword",
"ass"
)
val str = "This is the text that contains a badword"
val words = str.toLowerCase().split("\\s+".toRegex())
val containsBadWords = words.firstOrNull { it in nsfw } != null
println(containsBadWords)
will print
true
If you want a list of the "bad words":
val badWords = words.filter { it in nsfw }

How to append 2 strings in Kotlin?

I am trying to concatenate 2 String but not sure how to go about it.
this is my code:
val word = R.string.word
and i'm trying to append it with "$currentPage/5" inside the setText("$currentPage/5")
i tried to make it in this way setText("$word $currentPage/5")
and this way setText("${R.string.value} $currentPage/5")
and it did not work , it only shows me numbers not the text

try to use this:
val word = getString(R.string.word)
text_view.text = "$word $currentPage/5"
If you want to edit your value (e.g. current page) wrap it with {}
E.g.
val word = getString(R.string.word)
text_view.text = "$word ${currentPage/5}"
Remember to use proper kotlin syntax

In Kotlin, the concatenation of string can be done by **interpolation/templates**.
val a = "Its"
val b = "Kotlin!"
val c = "$a $b"
The output will be Its Kotlin!
Or we can alson do concatenate using the **+ / plus() operator**:
val a = "String"
val b = "Concatenate"
val c = a + b
val d =a.plus(b)
print(c)
The output will be: StringConcatenate
print(d)
The output will be: StringConcatenate
Or you can concatenate using the StringBuilder which is a normal way to do that.

To concatenate two string, we could do
val concatenatedWord = "${resources.getString(R.string.value)}:
${number/3}."
If R.string.value was "The result" and number was 15, value of concatenatedWord will be "The result: 5."
Or we could also concatenate using the + operator or using StringBuilder.
But if you do
textView.text = "${resources.getString(R.string.value)}: ${number/3}."
AS will warn "Do not concatenate text displayed with setText." so, in the case of setting concatenated text in textview, consider using
String.format("%s: %d.", resources.getString(R.string.value):
number/3)

As a future resource and answer why the accepted answer works:-
String Templates:-
Strings may contain template expressions, i.e. pieces of code that are evaluated and whose results are concatenated into the string.
How to implement these?
A template expression should start with a dollar sign ($) and consists of either a simple name:
when the expression is a simple variable.
val i = 10
println("i = $i") // prints "i = 10"
or else arbitrary expression in curly braces:
val s = "abc"
println("$s.length is ${s.length}") // prints "abc.length is 3"
Note :- Templates are supported both inside raw strings and inside escaped strings.

val nameOfAnimal = "fish"
val speciesClass = "is an Aquatic Vertebrate"
println(nameOfAnimal.plus(speciesClass))
println(nameOfAnimal+speciesClass)
println("$nameOfAnimal $speciesClass")
Results:
fishis an Aquatic Vertebrate
fishis an Aquatic Vertebrate
fish is an Aquatic Vertebrate

Android Get Country Emoji Flag Using Locale

I have seen that since Lollipop, Android has built in Emoji flags for different countries. Is it possible to use the devices locale to retrieve the Emoji flag for that country?
I wanted to insert the Emoji flag into a TextView which contains the user's location.

Emoji is a Unicode symbols. Based on the Unicode character table Emoji flags consist of 26 alphabetic Unicode characters (A-Z) intended to be used to encode ISO 3166-1 alpha-2 two-letter country codes (wiki).
That means it is possible to split two-letter country code and convert each A-Z letter to regional indicator symbol letter:
private String localeToEmoji(Locale locale) {
String countryCode = locale.getCountry();
int firstLetter = Character.codePointAt(countryCode, 0) - 0x41 + 0x1F1E6;
int secondLetter = Character.codePointAt(countryCode, 1) - 0x41 + 0x1F1E6;
return new String(Character.toChars(firstLetter)) + new String(Character.toChars(secondLetter));
}
Or in Kotlin, for example (assuming UTF-8):
val Locale.flagEmoji: String
get() {
val firstLetter = Character.codePointAt(country, 0) - 0x41 + 0x1F1E6
val secondLetter = Character.codePointAt(country, 1) - 0x41 + 0x1F1E6
return String(Character.toChars(firstLetter)) + String(Character.toChars(secondLetter))
}
Where 0x41 represents uppercase A letter and 0x1F1E6 is REGIONAL INDICATOR SYMBOL LETTER A in the Unicode table.
Note: This code example is simplified and doesn't have required checks related to country code, that could be not available inside the locale.

Based on this answer, I wrote a Kotlin version below using extension function.
I also added some checks to handle unknown country code.
/**
* This method is to change the country code like "us" into 🇺🇸
* Stolen from https://stackoverflow.com/a/35849652/75579
* 1. It first checks if the string consists of only 2 characters: ISO 3166-1 alpha-2 two-letter country codes (https://en.wikipedia.org/wiki/Regional_Indicator_Symbol).
* 2. It then checks if both characters are alphabet
* do nothing if it doesn't fulfil the 2 checks
* caveat: if you enter an invalid 2 letter country code, say "XX", it will pass the 2 checks, and it will return unknown result
*/
fun String.toFlagEmoji(): String {
// 1. It first checks if the string consists of only 2 characters: ISO 3166-1 alpha-2 two-letter country codes (https://en.wikipedia.org/wiki/Regional_Indicator_Symbol).
if (this.length != 2) {
return this
}
val countryCodeCaps = this.toUpperCase() // upper case is important because we are calculating offset
val firstLetter = Character.codePointAt(countryCodeCaps, 0) - 0x41 + 0x1F1E6
val secondLetter = Character.codePointAt(countryCodeCaps, 1) - 0x41 + 0x1F1E6
// 2. It then checks if both characters are alphabet
if (!countryCodeCaps[0].isLetter() || !countryCodeCaps[1].isLetter()) {
return this
}
return String(Character.toChars(firstLetter)) + String(Character.toChars(secondLetter))
}
Runnable Code Snippet
I also included a runnable Kotlin snippet using Kotlin Playground. In order to run the snippet you need to:
click "Show code snippet"
click "Run Code Snippet"
click the play button at the right top of the generated console
scroll to the bottom to see the result (it's hidden..)
<script src="https://unpkg.com/kotlin-playground#1.6.0/dist/playground.min.js" data-selector=".code"></script>
<div class="code" style="display:none;">
/**
* This method is to change the country code like "us" into 🇺🇸
* Stolen from https://stackoverflow.com/a/35849652/75579
* 1. It first checks if the string consists of only 2 characters: ISO 3166-1 alpha-2 two-letter country codes (https://en.wikipedia.org/wiki/Regional_Indicator_Symbol).
* 2. It then checks if both characters are alphabet
* do nothing if it doesn't fulfil the 2 checks
* caveat: if you enter an invalid 2 letter country code, say "XX", it will pass the 2 checks, and it will return unknown result
*/
fun String.toFlagEmoji(): String {
// 1. It first checks if the string consists of only 2 characters: ISO 3166-1 alpha-2 two-letter country codes (https://en.wikipedia.org/wiki/Regional_Indicator_Symbol).
if (this.length != 2) {
return this
}
val countryCodeCaps = this.toUpperCase() // upper case is important because we are calculating offset
val firstLetter = Character.codePointAt(countryCodeCaps, 0) - 0x41 + 0x1F1E6
val secondLetter = Character.codePointAt(countryCodeCaps, 1) - 0x41 + 0x1F1E6
// 2. It then checks if both characters are alphabet
if (!countryCodeCaps[0].isLetter() || !countryCodeCaps[1].isLetter()) {
return this
}
return String(Character.toChars(firstLetter)) + String(Character.toChars(secondLetter))
}
fun main(args: Array<String>){
println("us".toFlagEmoji())
println("AF".toFlagEmoji())
println("BR".toFlagEmoji())
println("MY".toFlagEmoji())
println("JP".toFlagEmoji())
}
</div>

When I first wrote this answer I somehow overlooked that I've only worked on Android via React Native!
Anyway, here's my JavaScript solution that works with or without ES6 support.
function countryCodeToFlagEmoji(country) {
return typeof String.fromCodePoint === "function"
? String.fromCodePoint(...[...country].map(c => c.charCodeAt() + 0x1f185))
: [...country]
.map(c => "\ud83c" + String.fromCharCode(0xdd85 + c.charCodeAt()))
.join("");
}
console.log(countryCodeToFlagEmoji("au"));
console.log(countryCodeToFlagEmoji("aubdusca"));
If you want to pass in the country codes as capital letters instead, just change the two offsets to 0x1f1a5 and 0xdda5.

You can get the country code very simple.
I want to talk about flag selection according to country code.
I wrote a class about it and it is very simple to use.
usage:
String countryWithFlag = CountryFlags.getCountryFlagByCountryCode("TR") + " " + "Türkiye";
Output : 🇹🇷 Türkiye
You can use it with Android TextView too :)
You can check out the class here
It works very well on Android 6 and above.

I am using this so easily.
Get the Unicode from here.
For Bangladesh flag it is U+1F1E7 U+1F1E9
Now,
{...
String flag = getEmojiByUnicode(0x1F1E7)+getEmojiByUnicode(0x1F1E9)+ " Bangladesh";
}
public String getEmojiByUnicode(int unicode){
return new String(Character.toChars(unicode));
}
It will show > (Bangladeshi flag) Bangladesh

I was looking for that too but I don't think it's possible yet.
Have a look here:
http://developer.android.com/reference/java/util/Locale.html
No mentioning about flags.
_
Alternately you can check the answer here:
Android Countries list with flags and availability of getting iso mobile codes
that might help you.

Regular expression with hebrew

I have text like:
לשלום קוראים לי משהmy test is עלות 39.40, כל מיני data 1.1.2015 ויש גם data 123456 מידע
This text have Hebrew and English characters, I need to eliminate all except the 6 digit number (may be 5, this num: 123456).
Can you help me with regular expression for this?
Tried:
String patternS = "[אבגדהוזחטיכךלמםנןסעפףצץקרשתa-fA-F0-9]{5,10}.*";
Pattern pattern = Pattern.compile(patternString);
With no success

To match everything except the number use:
\d+(?:[^\d]\d+)+|[\p{L}\p{M}\p{Z}\p{P}\p{S}\p{C}]+
String resultString = subjectString.replaceAll("\\d+(?:[^\\d]\\d+)+|[\\p{L}\\p{M}\\p{Z}\\p{P}\\p{S}\\p{C}]+", "");

This will give you every 6 didgit combination in your string.
(\d{6,6})
We can't give you a more detailled regex since we do now know the pattern of those strings.
In case there is always the "data " prefix you can also use this to make the pattern more accurate:
data (\d{6,6})

Try something like this:
String patternS = "(\d{5,6})";
Pattern pattern = Pattern.compile(patternS);
Matcher m = pattern.matcher(yourText);
int number = Integer.parseInt(m.group(1));
where yourText is the Hebrew/English text you want to match.

This would work for this specific example.
String s = " לשלום קוראים לי מש my test is עלות 39.40, כל מיני data 1.1.2015 ויש גם data 123456 מידע1234";
System.out.println(s.replaceAll(".*\\b(\\d{5,6})\\b.*", "$1"));