General
Strings
In Groovy you can use single quotes for "regular" strings. Documentation
buffer = "" // equivalent to buffer = ''
It's unlike Java where single quotes are for characters.
One exception to this is when using the $variable in Strings, you have to use double quotes for this.
buffer = "$buffer${textArray[i][j]}" // not equivalent to buffer = '$buffer${textArray[i][j]}'
Also, when placing variables in Strings, I tend to always wrap in { } even when it's not needed.
buffer = "${buffer}${textArray[i][j]}" // it's just more explicit
Method signature
This may be an unpopular opinion, but I like not using def in method signatures and instead using explicit types. It makes IDE suggestions and readability a lot better.
static void makePigLatin(String text){ // better than static void makePigLatin(def text){
To me def is only okay inside of a method.
eachWithIndex
I actually just looked this up writing the answer. You can use a method called eachWithIndex on arrays in place of a closure. Documentation
for (int i = 0; i < textArray.length; i++) { // or... textArray.eachWithIndex { e, i -> // where i is the index and e is the textArray[i] }
Scope
buffer and `translated are only ever used in your for loop. It's important to limit the scope of variables as much as possible. So it's probably better to declare them in the loop like so
// String buffer, translated // remove above for (int i = 0; i < textArray.length; i++) { String buffer = "" String translated = ""
Return a String instead of printing
Instead of your method being void make it return a String and remove all the println from it. Then from where you call makePigLatin instead do println makePigLating('some string here').
This limits the side-effects of the method. For tiny programs this is not a big deal but in larger projects knowing exactly what a method will do is very handy -- especially if the method is what is known as a "pure function" which means it literally has no side effects and its output is directly dependent on its output.
Consistent formatting
In some places you have spaces before braces (for (int i = 0; i < textArray.length; i++) {) and in others you don't (static void makePigLatin(String text){). It's less important whether or not you use them than how important it is to be consistent. Personally I put spaces before them.
Specifics
The below code is a little odd to me, it's saying in the ith word in the jth character, find each a in the jth character that is any of the vowels.
textArray[i][j].find { a -> vowels.any {a.contains(it)}}
No need to do a find on a single character. The below is a cleaner way to me.
vowels.any { vowel -> vowel.equals(textArray[i][j]) }
The below
buffer = "$buffer${textArray[i][j]}"
Can simply be
buffer += textArray[i][j]
