Removing unncecessary parts from String - kotlin

Question

I'm consuming a client that I cannot change and it sends me data that looks like that:
"BOOKING - PAID (price.amount=70, price.currency=EUR)"
and I would like to retrieve from that only 70 EUR
What is the best way to do such thing in kotlin? I didn't find any removeAll("", "", ...) functions for String, only replace but would have to chain them to remove both price.amount and price.currency.
EDIT:
Need to get BOOKING - PAID (70 EUR) actually, forgot about that part.

Answer 1

Thinking about it and as you updated your question to really remove only a part from the string, here are some approaches for removing several strings from a given string:
Using regex:
input.replace("""(price\.(amount|currency)=|,)""".toRegex(), "")
Using a list of strings to remove:
sequenceOf(input, "price.amount=", ",", "price.currency=")
.reduce { acc, rm -> acc.replace(rm, "") }
// alternatively using var:
var input = TODO()
sequenceOf("price.amount=", ",", "price.currency=")
.forEach { input = input.replace(it, "") }
Still: most of the time I would rather take the other route: extracting the information you require and just print that, as also Baptiste has shown in his answer. Otherwise you may start to expose answers of that service you didn't want to expose in the first place.

Answer 2

This sounds like a job for regular expressions!
fun main(args: Array<String>) {
val str = "BOOKING - PAID (price.amount=70, price.currency=EUR)"
// The expressions between parentheses will map to groups[1], groups[2] and groups[3] respectively
val reg = Regex("""(.*) \(price\.amount=([0-9]+), price\.currency=([A-Z]+)\)""")
// Apply the regular expression on the string
val results = reg.find(str)
results?.groupValues?.let { groups ->
// If results and groupValues aren't null, we've got our values!
val type = groups[1]
val price = groups[2]
val currency = groups[3]
println("$type ($price $currency)") // BOOKING - PAID (70 EUR)
}
// Or as suggested by #Roland:
results?.destructured?.let { (type, price, currency) ->
println("$type ($price $currency)") // BOOKING - PAID (70 EUR)
}
}
Regular expressions allow you to take a string as entry, and find a pattern in it. They're quite used in all languages, you can find more info about them all over the place.
EDIT: edited for the updated question. I chose to treat "BOOKING - PAID" as a single string, but there's an infinite number of ways to do it, depending on your granularity needs; and honestly, at that point a regex might be a bit overkill. :)

Answer 3

Without regex by string manipulation and assuming that this is the pattern:
fun main(args: Array <String> ) {
val str = "BOOKING - PAID (price.amount=70, price.currency=EUR)"
val type = str.substringBefore("(").trim()
val price = str.substringBeforeLast(",").substringAfter("=")
val currency = str.substringAfterLast("=").substringBefore(")")
val result = "$type ($price $currency)"
println(result)
}
will print
BOOKING - PAID (70 EUR)
Edit: I use str.substringBeforeLast(",") to get the price, in case , could be used as a delimeter for decimal part in the number