One month with Kotlin: singleton example

singletonExample.java

// Using Singleton on Kotlin
public object MySingleton {
  
  public fun foo() {
  }
  
}

// And use it on Kotlin
MySingleton.foo()

//------------------------------------------------------------------------------

// Using Singletons in Java 7
public class MySingleton {
  
  private static MySingleton instance;

  private MySingleton() {
  }
  
  public static MySingleton getInstance(){
    if(instance == null) {
      instance = new MySingleton();
    }
    return instance;
  }

  public void foo() {
  }

}

//Using use it in Java
MySingleton.getInstance().foo()

public modifiers are the default modifiers in Kotlin so they are not mandatory

Hi,
your example in Java is not thread safe and so could be a no Singleton.
A better example could be
`
public class Singleton {
private static class SingletonHolder{
private static final Singleton INSTANCE = new Singleton();
private SingletonHolder(){}
}
private Singleton(){}

public static Singleton getInstance(){
return SingletonHolder.INSTANCE;
}
}`
This way you don't use synchronise which break the performance and you use JVM static way of loading variables.