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Java

I need help to end a infinitive recursive statement in Java

I'm trying to get this method to run smoothly but I can not seem to figure out how to stop my recursive statement to infinitely. I thought I could solve it with a do..while loop but that did not work for me. Any help would be greatly appreciated!

Here is the snippet of code I'm having trouble with.

  String sentence = null;
    String[] conjunction = {"and", "or", "but", "because"};
    int c = (int)(Math.random()*conjunction.length);

    boolean repeat = false;

    do {
        sentence = SimpleSentence() + (conjunction[c] + Sentence());
    } while (repeat == true);

    return sentence;
 }

Here is the full code (incase it helps to look at):

public class RandomSentences {




    public static void main(String[] args) {

     if (Math.random() > .5) 
         Sentence();

     else
         SimpleSentence();

     }

    public static String Sentence() {

    String sentence = null;
    String[] conjunction = {"and", "or", "but", "because"};
    int c = (int)(Math.random()*conjunction.length);

    boolean repeat = false;

    do {
        sentence = SimpleSentence() + (conjunction[c] + Sentence());
    } while (repeat == true);

    return sentence;
 }

     public static String SimpleSentence() {


    String[] properNoun = {"Fred", "Jane", "Richard Nixon", "Miss America"};
    String[] commonNoun = {"man", "woman", "fish", "elephant", "unicorn"};
    String[] determiner = {"a", "the", "every", "some"};
    String[] adjective = {"big", "tiny", "pretty", "bald"};
    String[] intransitiveVerb = {"runs", "jumps", "talks", "sleeps"};
    String[] transitiveVerb = {"loves", "hates", "sees", "knows", "looks for", "finds"};


     int pN = (int)(Math.random()*properNoun.length);
     int cN = (int)(Math.random()*commonNoun.length);
     int d = (int)(Math.random()*determiner.length);
     int a = (int)(Math.random()*adjective.length);
     int iV = (int)(Math.random()*intransitiveVerb.length);
     int tV = (int)(Math.random()*transitiveVerb.length);

     String nounPhrase = null;
     String verbPhrase = null;


     String simpleSentence = null;

     double randomNounPhrase = Math.random();
     double randomVerbPhrase = (Math.random()*4) +1;
     int i = (int) randomVerbPhrase;

     double sentenceOrSentencePhrase = Math.random();

     if (randomNounPhrase > randomNounPhrase / 2)
         nounPhrase = properNoun[pN];
     else 
         nounPhrase = determiner[d] + adjective[a] + commonNoun[cN] + "who" + verbPhrase;

     switch (i) {
         case 1: verbPhrase = intransitiveVerb[iV];
                 break;
         case 2: verbPhrase = transitiveVerb[tV] + nounPhrase;
                 break;
         case 3: verbPhrase = "is" + adjective[a];
                 break;
         case 4: verbPhrase = "believes that" + simpleSentence;
                 break;   
     }

        simpleSentence = nounPhrase + verbPhrase;

        return simpleSentence;

     }


}
Patrik Horváth
Patrik Horváth
11,085 Points

recursive methods stops when they see RETURN or you can throw Exception but its Dirty xD if you cant use Return so throw exception is only way to do it i think

2 Answers

Seth Kroger
Seth Kroger
56,403 Points

With a recursive function you either return 1) a value resulting from calling the function again, or 2) return a straight value ending the recursion. The trick isn't so much figuring out how to stop but when to stop. Once you figure out determining when you should stop, the rest should be easy.

Patrik Horváth
Patrik Horváth
11,085 Points

recursive methods stops when they see RETURN or you can throw Exception but its Dirty xD if you cant use Return so throw exception is only way to do it i think

PS use more OOP next time writing all in main method is little bit mess

for exapmle xD with additional Attribute (boolean)

public static void main(String[] args) {

    boolean shouldIRepeat = true;

     if (Math.random() > .5) 
         Sentence();

     else
         SimpleSentence();

     }

    public static String Sentence() {

    String sentence = null;
    String[] conjunction = {"and", "or", "but", "because"};
    int c = (int)(Math.random()*conjunction.length);

    boolean repeat = false;

    while(shouldIRepeat) {
        shouldIRepeat = false;
        sentence = SimpleSentence() + (conjunction[c] + Sentence());
    }

    return sentence;
 }
}