How do I figure out if an array contains an element?
I thought there might be something like [1, 2, 3].includes(1) which would evaluate as true.
Some syntax sugar
1 in [1,2,3]
.contains() is the best method for lists, but for maps you will need to use .containsKey() or .containsValue()
[a:1,b:2,c:3].containsValue(3)
[a:1,b:2,c:3].containsKey('a')
For lists, use contains:
[1,2,3].contains(1) == true
If you really want your includes method on an ArrayList, just add it:
ArrayList.metaClass.includes = { i -> i in delegate }
You can use Membership operator:
def list = ['Grace','Rob','Emmy']
assert ('Emmy' in list)
Membership operator Groovy
IMPORTANT Gotcha for using .contains() on a Collection of Objects, such as Domains. If the Domain declaration contains a EqualsAndHashCode, or some other equals() implementation to determine if those Ojbects are equal, and you've set it like this...
import groovy.transform.EqualsAndHashCode
#EqualsAndHashCode(includes = "settingNameId, value")
then the .contains(myObjectToCompareTo) will evaluate the data in myObjectToCompareTo with the data for each Object instance in the Collection. So, if your equals method isn't up to snuff, as mine was not, you might see unexpected results.
def fruitBag = ["orange","banana","coconut"]
def fruit = fruitBag.collect{item -> item.contains('n')}
I did it like this so it works if someone is looking for it.
You can also use matches with regular expression like this:
boolean bool = List.matches("(?i).*SOME STRING HERE.*")
Related
global with sharing class test1 {
global Map<SObjectField, SObject> ConvertMap(List<SObject> listToConvert){
List<SObject> listToConvert = new List<SObject>;
Map<SObjectField, SObject> mapTest = new Map<SObjectField, SObject>;
mapTest.putAll(listToConvert);
return mapTest;
}
I've written this code, but it doesn't respect the request 'cause I can't put SObjectField as method parameter since the Map won't recognize the variable.
Does anyone have suggestions on how to do it?
Thank you in advance.
Do you really need SobjectField as map keys? the special class? If you're fine with strings as keys then there's a builtin, getPopulatedFieldsAsMap()
If you absolutely need SobjectField (I don't even know if it's serializable and can be passed to integrations, LWC etc)... You'd have to loop and marry the results to something like
Schema.describeSObjects(new List<String>{'Account'})[0].fields.getMap()
I am working with a method which filters the preferences which match with the ids, I am using the contains method, but even though the values are the same, the contains is showing a false in each iteration. The method looks like:
private fun filterPreferencesByIds(context: MyPodCastPresenterContext): List<FanPreferences> {
return context.preferences?.filter {
context.ids.contains(it.id)
}
}
The values of the arrays are:
for the context.ids:
"B52594F5-80A4-4B18-B5E2-8F7B12E92958" and "3998EDE7-F84B-4F02-8E15-65F535080100"
And for the context.preferences:
But even though, when the first and the final ids have the same id value as the context.ids, the contains is false in the debug. I think it could be related with the types in the context.ids rows Json$JsonTextNode. Because when I did the same with numeric values hardcoded the compare is successful.
Any ideas?
Thanks!
If the type of FanPreferences.id is String and the type of context.ids list element is JsonTextNode, you won't find an element equal to the given id string, because it's not of String type.
Try mapping your context ids to the list of strings before filtering:
val ids = context.ids.map { it.toString() }.toSet()
return context.preferences?.filter {
ids.contains(it.id)
}
Note that calling toString() on JsonTextNode might be not the best way to get the string data from it. It's better to consult the API documentation of that class to find it out.
Scala beginner who is trying to store values obtains in a Scala foreach loop but failing miserably.
The basic foreach loop looks like this currently:
order.orderList.foreach((x: OrderRef) => {
val references = x.ref}))
When run this foreach loop will execute twice and return a reference each time. I'm trying to capture the reference value it returns on each run (so two references in either a list or array form so I can access these values later)
I'm really confused about how to go about doing this...
I attempted to retrieve and store the values as an array but when ran, the array list doesn't seem to hold any values.
This was my attempt:
val newArray = Array(order.orderList.foreach((x: OrderRef) => {
val references = x.ref
}))
println(newArray)
Any advice would be much appreciated. If there is a better way to achieve this, please share. Thanks
Use map instead of foreach
order.orderList.map((x: OrderRef) => {x.ref}))
Also val references = x.ref doesn't return anything. It create new local variable and assign value to it.
Agree with answer 1, and I believe the reason is below:
Return of 'foreach' or 'for' should be 'Unit', and 'map' is an with an changed type result like example below:
def map[B](f: (A) ⇒ B): Array[B]
Compare To for and foreach, the prototype should be like this
def foreach(f: (A) ⇒ Unit): Unit
So If you wanna to get an changed data which is maped from your source data, considering more about functions like map, flatMap, and these functions will traverse all datas like for and foreach(except with yield), but with return values.
I want to encode this algorithm In Elixir:
var name = generate_name();
while (check_if_exists(name)) {
name = generate_name();
}
I can't encode that the same way in Elixir because there must more idiomatic and functional way. How can I do that then?
Elixir is an Immutable programming language. That means you cannot modify the value of variable, only re-bind it. Hence, the classic while-loop doesn't exist in Elixir.
But, you can implement this using recursion:
def get_name do
name = generate_name()
case check_if_exists(name) do
true -> get_name()
false -> name
end
end
Another possibility is to create an infinite stream of names, then find the first name that is available:
Stream.repeatedly(&generate_name/0)
|> Enum.find(&check_if_exists/1)
I'm not a programmer, but I find myself writing some simple ruby and aren't sure about a few things.
I have the following function
def resolve_name(ns_name)
ip = Resolv.getaddress(ns_name)
return ip
end
and the array
array = ['ns-1.me.com', 'ns-2.me.com']
What I want to do is to pass every element in the array to the function to be evaluated, and spit out to... something. Probably a variable. Once I have the resolved IPs I'll be passing them to an erb template. Not quite sure yet how to handle when there may be 1 to 4 possible results either.
What I want think I need to do is do an each.do and typecast to string into my function, but I haven't been able to figure out how to actually do that or phrase my problem properly for google to tell me.
http://ruby-doc.org/core-2.0.0/doc/syntax/calling_methods_rdoc.html#label-Array+to+Arguments+Conversion Doesn't quite have what I'm looking for.
irb(main):010:0> resolved = resolve_name(array)
TypeError: no implicit conversion of Array into String
Any suggestions?
Take a look at the documentation for ruby's Enumerable, which arrays implement. What you're looking for is the map method, which takes each element of an enumerable (i.e. an array) and passes it to a block, returning a new array with the results of the blocks. Like this:
array.map{|element| resolve_name(element) }
As an aside, in your method, you do not need to use a local variable if all you're doing with it is returning its value; and the return statement is optional - ruby methods always return the result of the last executed statement. So your method could be shortened to this:
def resolve_name(ns_name)
Resolv.getaddress(ns_name)
end
and then you really all it's doing is wrapping a method call in another. So ultimately, you can just do this (with array renamed to ns_names to make it self-explanatory):
ns_names = ['ns-1.me.com', 'ns-2.me.com']
ip_addresses = ns_names.map{|name| Resolv.getaddress(name) }
Now ip_addresses is an array of IP addresses that you can use in your template.
If you pass an array you could do:
def resolve_name(ns_name)
res = []
ns_name.each do |n|
res << {name: n, ip: Resolv.getaddress(name) }
end
res
end
And get an array of hashes so you know which address has which ip