First Groovy

 class Sample {
     def names = ["anna", "annie", "tommy", "bobby", "doggy"];

     public static void main(def args) {
         //Loop
         for (i in 0..5) {
             println "Hello, World!"
         }

         //Closure
         def sample = new Sample();
         //Operation of array
         sample.names << "Terry";
         println sample.names;

         println "-------"
         //lambda expression   each
         sample.names.each({ e -> println(e) });

         println "-------"
         //keyword it.
         sample.names.each { println it }

         println "-------"

         //filter
         List<String> matched = sample.names.findAll { e -> e.contains("o") }
         matched.each { println it }

         println "-------"
         //sort
         sample.names << "William";
         sample.names << "bob";
         List<String> sorted = sample.names.sort({ e -> e.length() })
         sorted.each { println it }

         println "-------"
         //grouped
         Map<Boolean, String> grouped = sample.names.groupBy { e -> e.contains("o") }
         grouped.each { key, value -> println "$key:$value" }
     }
 }