The **```kotlin.collections``` package** is part of Kotlin's standard library. It contains all collection types, including ```Map```, ```List```, ```Set```, etc.

The package provides the **```ArrayList``` class**, which is a mutable list. This class uses a dynamic resizable array as the backing storage.

#   
## The `contains()` method

The `ArrayList` class includes the **`contains()` method** which checks for the presence of the specified input element in the array list.

## Syntax
```
fun contains(element: E): Boolean
```

## Parameters
- This method takes the object to search in the array list as input.

## Return value
This method returns `true` if the element is present in the list and `false` if the element is not present.

## Things to note
- `ArrayList` follows the sequence of insertion of elements.

- It is allowed to contain duplicate elements.

The illustration below shows the function of the `contains()` method.

## Code
The ```ArrayList``` class is present in the ```kotlin.collection``` package and is imported by default in every Kotlin program.

fun main(args : Array<String>) {
    val companyList = ArrayList<String>()
    
    companyList.add("Apple")
    companyList.add("Google")  
    companyList.add("Microsoft")  
    companyList.add("Netflix")  
    
    println("Printing ArrayList elements--")  
    println(companyList)  

    println("Checking 'Microsoft' presence in array list using contains() : ${companyList.contains("Microsoft")}")
    println("Checking 'Adobe' presence in array list using contains() : ${companyList.contains("Adobe")}")
}

## Explanation
- First, we create an empty ```ArrayList``` to store the strings.

- Next, we add a few company names to the ```ArrayList``` object, using the ```add()``` method such as: ```"Google"```, ```"Apple"```, ```"Microsoft"```, and  ```"Netflix"```.
- Next, we call the  ```contains()``` method by passing `Microsoft` as input and it returns `true`.
- We again call the  ```contains()``` method by passing `Adobe` as input and it returns `false`.




What is the ArrayList.contains() method in Kotlin?

The contains() method

Syntax

Parameters

Return value

Things to note

Code

Explanation

The `contains()` method