What is the equivalent of Java static methods in Kotlin?

Question

There is no static keyword in Kotlin.

What is the best way to represent a static Java method in Kotlin?

Answer 1

In Java, we can write in below way

class MyClass {
  public static int myMethod() { 
  return 1;
  }
}

In Kotlin, we can write in below way

class MyClass {
  companion object {
     fun myMethod() : Int = 1
  }
}

a companion is used as static in Kotlin.

Answer 2

Kotlin has no any static keyword. You used that for java

 class AppHelper {
        public static int getAge() {
            return 30;
        }
    }

and For Kotlin

class AppHelper {
        companion object {
            fun getAge() : Int = 30
        }
    }

Call for Java

AppHelper.getAge();

Call for Kotlin

AppHelper.Companion.getAge();

I think its working perfectly.

Answer 3

You can achieve the static functionality in Kotlin by Companion Objects

• Adding companion to the object declaration allows for adding the static functionality to an object even though the actual static concept does not exist in Kotlin.
• A companion object can access all members of the class too, including the private constructors.
• A companion object is initialized when the class is instantiated.

• A companion object cannot be declared outside the class.

  class MyClass{
  
      companion object {
  
          val staticField = "This is an example of static field Object Decleration"
  
          fun getStaticFunction(): String {
              return "This is example of static function for Object Decleration"
          }
  
      }
  }
  

Members of the companion object can be called by using simply the class name as the qualifier:

Output:

MyClass.staticField // This is an example of static field Object Decleration

MyClass.getStaticFunction() : // This is an example of static function for Object Decleration

Answer 4

All static member and function should be inside companion block

  companion object {
    @JvmStatic
    fun main(args: Array<String>) {
    }

    fun staticMethod() {
    }
  }