Kotlin - Idiomatic way to check array contains value

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What's a idiomatic way to check if an array of strings contains a value in kotlin? Just like ruby's #include?.

I though about:

array.filter { it == "value" }.any()

Is there a better way?

The equivalent you are looking for is the contains operator.

array.contains("value") 

Kotlin offer an alternative infix notation for this operator:

"value" in array

It's the same function called behind the scene, but since infix notation isn't found in Java we could say that in is the most idiomatic way.

contains, operator fun ShortArray.contains(element: Short): Boolean This method allows to use the x in map syntax for checking whether an object is contained in the� In the above program, we've used a non-primitive data type String and used Arrays's stream() method to first convert it to a stream and anyMatch() to check if array contains the given value toFind. Here's the equivalent Java code: Java program to check if array contains a given value.

You could also check if the array contains an object with some specific field to compare with using any()

listOfObjects.any{ object -> object.fieldxyz == value_to_compare_here }

Array, contains. Common. JVM. JS. Native. 1.0. abstract fun contains(element: @ UnsafeVariance E): Boolean. Checks if the specified element is contained in this � Again, for the same array, if we check if it contains 10 or 11, it should return false because neither of these numbers exists in the array. In Kotlin, we have different ways to do that. Let’s check them one by one :

You can use the in operator which, in this case, calls contains:

"value" in array

Kotlin Program to Check if An Array Contains a Given Value, get. Returns the array element at the specified index. This method can be called using the index operator fun <T> Array<out T>.contains(element: T): Boolean. This article explores different ways to check whether an array contains the specified value or not in Kotlin. 1. contains() function The utility function to check presence of an element in an array is with contains() function. [crayon-5f0187fe16f8b189094473/] 2. ‘In’ operator Kotlin provides In operator which is an alternative syntax for contains …

Using in operator is an idiomatic way to do that.

val contains = "a" in arrayOf("a", "b", "c")

Kotlin – Idiomatic way to check array contains value, Kotlin Program to Check if An Array Contains a Given Value. fun main(args: Array<String>) { val num = intArrayOf(1, 2, 3, 4, 5) val toFind = 3 var found = false for (n in num) { if (n == toFind) { found = true break } } if (found) println("$toFind is found.") else println("$toFind is not found.") } import java. util. You can always use the for loop or Array.indexOf() method, but ES6 has added plenty of more useful methods to search through an array and find what you are looking for with ease. indexOf() Method. The simplest and fastest way to check if an item is present in an array is by using the Array.indexOf() method. This method searches the array for

Here is code where you can find specific field in ArrayList with objects. The answer of Amar Jain helped me:

listOfObjects.any{ it.field == "value"}

In Kotlin, how to check contains one or another value?, What's a idiomatic way to check if an array of strings contains a value in kotlin? Just like ruby's #include? . #include? I though about: array.filter� I have an ArrayList and when it contains a specific value, I want to observe the list and check when this value has been removed. What's the best way to do it in Kotlin/Android? I've implemented it so far using LiveData, but it seems like overkill. I just have a hunch that there's a better solution.

Kotlin Array, But if I want to check if 2 or 3 are in arr , what is the most idiomatic way to do it it to a stream and anyMatch () to check if array contains the given value toFind. Short summary: since Kotlin 1.4, lambdas returning values of kotlin.Result type will return boxed value instead of unboxed. Deprecation cycle: < 1.4: old behavior (see details in the issue) >= 1.4: behavior changed; Comparing floating point values in array/list operations contains, indexOf, lastIndexOf: IEEE 754 or total order. Issue: KT-28753

Kotlin - Idiomatic way to check array contains value, size is fixed. To learn more about the array data structure, check out Array tutorials. There are two ways to define an array in Kotlin. Using the The above code sets the value of the second element in the array to 3 The simplest and most commonly used idiom when it comes to traversing an array is to use the for-loop. If i understood it correctly then he is asking for best way to check null in Kotlin, not which approach generates best byte-code.@BenitoBertoli answer looks promising, it's reduces boilerplate code – imGs Dec 1 '17 at 12:30

Check if list contains a value, in Kotlin, What's a idiomatic way to check if an array of strings contains a value in kotlin? Just like ruby's #include? . #include? I though about: array.filter� bool Contains(const std::vector<int> &list, int x) { return std::find(list.begin(), list.end(), x) != list.end(); }

Comments
  • When I try this in Kotlin I get a "Type inference failed. The value of the type parameter T should be mentioned in the input Types." private var domainsArray = arrayOf("@ebay.com", "@google.com", "@gmail.com", "@umd.edu") var domainFound = Arrays.asList(domainsArray).contains(email)
  • Just write var domainFound = domainsArray.contains(email) or more idiomatic var domainFound = email in domainsArray