Change from finding max number to find words in array

Question

I have a function that is searching for max number in the array. I want to make the function to search for more than one word that is entered from console. As example I enter two words(car,ride) they're added to array and then "surasti" function is comparing them if they're in the array. I have tried to do it on my own, but I'm a started and it seems too hard :(

Function that is searching:

public static produktas[] surasti (produktas G[], int n){
    produktas A[] = new produktas[1]; 
    produktas max = G[0];
    for (int i=1; i<n; i++)
        if (max.gautiSvori()<G[i].gautiSvori()) max = G[i];
    A[0]=max;
    return A;
}

The code that is calling that function (A is the array that you have to search in.):

    case 5:
        B = surasti(A, n);
        System.out.println("Sunkiausias gyvunas yra:");
        spausdinti_sar_ekrane(B, B.length);
        break;

The produktas class:

class produktas {
    private String pavadinimas;
    private String salis;
    private Double svoris;
    private Double kaina;

    produktas() {}
    produktas(String pav, String salis, double svoris, double kaina){
        pavadinimas = pav;
        this.salis = salis;
        this.svoris = svoris;
        this.kaina = kaina;
    }



    public String gautiPav (){
        return pavadinimas;
    }

    public String gautiSali (){
        return salis;
    }

    public double gautiSvori (){
        return svoris;
    }

    public double gautiKaina (){
        return kaina;
    }
}

When I try to change the function to this (don't know if its working fine, can't test it):

public static produktas[] surasti (produktas G[], int n){
        try{
        BufferedReader in = new BufferedReader (new InputStreamReader (System.in));
        produktas A[] = new produktas[5];
        for (int j=0; j<5; j++){
        System.out.println("Kokio produkto ieskosime?");
        String found = in.readLine();
        for (int i=1; i<n; i++){
            if (found.equals(G[i].gautiPav())){ 
                A[j] = G[i];
            }
        }
    } 
    return A; 
    } catch(IOException ie){
            ie.printStackTrace();
        }
    }

When I try this code I get this error at public static produktas[] surasti (produktas G[], int n){ line:

This method must return a result of type produktas[]

Answer 1

Your comparison operator is not correct. Try the following code :

public static produktas surasti(produktas G[]) {
    produktas max = G[0];
    for (int i = 0; i < G.length; i++) {
        if (max.gautiSvori() < G[i].gautiSvori()) {
            max = G[i];
        }
    }
    return max;
}

You need to pass the array and set the first element of the array as the maximum as by default first. Next iterate through the array and check whether there is a produktas with a higher value of svoris. If so, change the max to point to this new produktas. At the end of the for loop, you will now have the max set to the produktas with the highest value of svoris.

There are few things in the code that you can fix for better quality code.

1. You don't need to pass the array size to the surasti method. We can just do a G.length (in the code above I have done that).
2. Best practice is to user Camel case for Java classes. Therefore instead of produktas, use Produktas
3. Use meaningful names for variables instead of A, G, etc

Answer 2

For the correctly complied code update your method to have a return in catch block as well.

public static produktas[] surasti(produktas G[], int n) {
    try {
        BufferedReader in = new BufferedReader(new InputStreamReader(
                System.in));
        produktas A[] = new produktas[5];
        for (int j = 0; j < 5; j++) {
            System.out.println("Kokio produkto ieskosime?");
            String found = in.readLine();
            for (int i = 1; i < n; i++) {
                if (found.equals(G[i].gautiPav())) {
                    A[j] = G[i];
                }
            }
        }
        return A;
    } catch (IOException ie) {
        ie.printStackTrace();
        return null; // Expected return from catch block
    }
}

To understand the issue properly start using IDE like eclipse rather than simply using a notepad and compiling code through java/javac

A more suitable code would be like as below. Type q in console when u want to exit from the program.

public static produktas[] surasti(produktas G[], int n) {
    BufferedReader consoleReader = null;
    produktas produktasFound[] = new produktas[5]; // Initalize array to store the produkt found
    try {
        consoleReader = new BufferedReader(new InputStreamReader(System.in));
        boolean exit = false;
        produktas produktasFound[] = new produktas[5];
        int j = 0;//current produktFound index

        while (!exit) {
            System.out.println("Kokio produkto ieskosime?");
            String produktPav = in.readLine();

            if ("q".equals(produktPav)) {
                exit = true;
            } else {
                for (int i=1; i<n; i++){
                    if (found.equals(G[i].gautiPav())){ 
                        A[j] = G[i];
                        j++; 
                    }
                }
            }

            if(j == 5)
                exit = true;
        }
        return produktasFound; // return all the 5 produktas found
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (consoleReader != null) {
            try {
                consoleReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    return produktasFound; //If no produkt is found from the array returned is blank
}