How to use "continue" in groovy's each loop

61.4k views Asked by At

I am new to groovy (worked on java), trying to write some test cases using Spock framework. I need the following Java snippet converted into groovy snippet using "each loop"

Java Snippet:

List<String> myList = Arrays.asList("Hello", "World!", "How", "Are", "You");
for( String myObj : myList){
    if(myObj==null) {
        continue;   // need to convert this part in groovy using each loop
    }
    System.out.println("My Object is "+ myObj);
}

Groovy Snippet:

def myObj = ["Hello", "World!", "How", "Are", "You"]
myList.each{ myObj->
    if(myObj==null){
        //here I need to continue
    }
    println("My Object is " + myObj)
}
3

There are 3 answers

3
Vampire On BEST ANSWER

Either use return, as the closure basically is a method that is called with each element as parameter like

def myObj = ["Hello", "World!", "How", "Are", "You"]
myList.each{ myObj->
    if(myObj==null){
        return
    }
    println("My Object is " + myObj)
}

Or switch your pattern to

def myObj = ["Hello", "World!", "How", "Are", "You"]
myList.each{ myObj->
    if(myObj!=null){
        println("My Object is " + myObj)
    }
}

Or use a findAll before to filter out null objects

def myList = ["Hello", "World!", "How", "Are", null, "You"]
myList.findAll { it != null }.each{ myObj->
    println("My Object is " + myObj)
}

Or if you are concerned that you first iterate through the whole collection to filter and only then start with the each, you can also leverage Java streams

def myList = ["Hello", "World!", "How", "Are", null, "You"]
myList.stream().filter { it != null }.each{ myObj->
    println("My Object is " + myObj)
}
0
injecteer On

you can either use a standard for loop with continue:

for( String myObj in myList ){
  if( something ) continue
  doTheRest()
}

or use return in each's closure:

myList.each{ myObj->
  if( something ) return
  doTheRest()
}
1
Andrew_CS On

You could also only enter your if statement if the object isn't null.

def myObj = ["Hello", "World!", "How", "Are", "You"]
myList.each{ 
    myObj->
    if(myObj!=null){
        println("My Object is " + myObj)
    }
}