2. Java Static Method equivalent in Kotlin

1. Java static Classes and Methods

public class Foo {
 
    public static String exe() {
        return "javasampleapproach.com";
    }
 
    public static String upperCase(String s) {
        return s.toUpperCase();
    }
 
    public static class Bar {
 
        public static String bar() {
            return "Bar";
        }
    }
 
    public static class Num {
 
        public static Integer doubleInt(Integer i) {
            return new Integer(i.intValue() * 2);
        }
    }
}

2. Equivalent in Kotlin

class Foo {
 
    companion object {
 
        fun exe(): String = "javasampleapproach.com"
        fun upperCase(s : String) : String = s.toUpperCase()
    }
 
    object Bar {
 
        fun bar(): String = "Bar"
    }
 
    object Num {
 
        fun doubleInt(i: Int): Int = i * 2
    }
}

3. Run & Check Result

package com.kotlinsample.staticmethod
 
fun main(args: Array<String>) {
 
    val static = Foo.exe()
    println(static)
    
    val upper = Foo.upperCase("javasampleapproach.com")
    println(upper)
    
    val bar = Foo.Bar.bar();
    println(bar)
    
    val num = Foo.Num.doubleInt(3);
    println(num)
}

Kotlin