CODEWITHSUNDEEP
javaarraysbooleaninfinite-loop
Duncan Adkins
Duncan Adkins

Reputation: 53

How to check a boolean array for any instances of true and then print those instances from a corresponding array?

I have two arrays, need[ ] and bought[ ]. need[ ] is a String array containing 7 different items that are considered bought(true) or need(false) according to the corresponding index value of the boolean bought[] array. I want to print a list of the bought items only when items have actually been bought. However, my current technique is producing an infinite loop of the item at need[1].

public static void listSupplies(String[] need, boolean[] bought){
        /*Line of code in the while loop checks the whole array for an instance of 'true'*/
        if(areAllFalse(bought) == true){
            System.out.println("Inventory:");
            for (int i = 0; i < need.length; i++) { 
                if(bought[i] == true){
                    System.out.print(need[i] + " "); System.out.println(" "); break;
                }
            }
            System.out.println("");
        }
        System.out.println("Need:");
        for (int i = 0; i < need.length; i++) { 
            while(bought[i] == false){
                System.out.print(need[i] + " "); System.out.println(" ");
            }
        }
        System.out.println("");
        mainMenu();
    }
    //Checks to see if the array contains 'true'
    public static boolean areAllFalse(boolean[] array){
        for(boolean val : array){
            if(val) 
                return true;
        } 
        return false;
    }

(Before this code, the arrays were declared as such:)

String[] needInit = {"Broom", "School robes", "Wand", "The Standard Book of Spells", "A History of Magic", "Magical Drafts and Potions", "Cauldron"};
boolean bought[] = new boolean[7];

Upvotes: 2

Views: 584

Answers (1)

Eran
Eran

Reputation: 393781

Your while loop causes the infinite loop. You don't need it. If you only want to print the bought items :

Change :

    for (int i = 0; i < need.length; i++) { 
        while(bought[i] == false){ // here's the cause of the infinite loop
            System.out.print(need[i] + " "); System.out.println(" ");
        }
    }

To :

    for (int i = 0; i < need.length; i++) { 
        if (bought[i]){
            System.out.print(need[i] + " "); 
        }
    }
    System.out.println(" ");

Upvotes: 5

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