Finding specific value inside an Array (not List)

Question

I am learning about arrays and I did quiet a few experiments, most of them went well, however now I'm stuck. What I want to archive is, find if an specific value (String, int or whatever), exists inside an Array and if it does, use that value for something i.e the code below which I basically count how many times that value was present inside the array:

package arraysOnly;
import java.util.*;
public class ArrayContainsString
{
    public static void main(String[]args)
        {       
            Scanner sc = new Scanner(System.in);
            int arraySize = 0;
            int wordCount = 0;

            System.out.println("How many words are you gonna type?: ");
            arraySize = sc.nextInt();

            String[] words = new String[arraySize];     // Simple array, the size of which will be decided from the user-input

            for(int count = 0; count < arraySize; count++)
            {
                System.out.println("Enter your " + (count+1) + ": ");
                words[count] = sc.next();
            }

            //Basically this is the part I'm having troubles
             if(in_array("ubt", $words)
            {
                 wordCount++;
            }
        }
}

I know about this,

if(Arrays.asList(words).contains("ubt"));

which basically converts the array into an List / ArrayList or whatever, however I want to treat this as an array only if possible.

Bohemian · Accepted Answer · 2015-08-19 18:05:26Z

2

An array is the wrong data structure; a Set is the weapon of choice:

Set<String> words = new HashSet<>()
for (int count = 0; count < arraySize; count++) {
    System.out.println("Enter your " + (count+1) + ": ");
    words.add(sc.next());
}

if (words.contains("ubt"))
    wordCount++;
}

The contains() method of a HashSet completes in constant time not matter how large the set is. Although performance is irrelevant for small input sizes like this usage, it's good to get in the habit of choosing the right tools for the job. It also makes your code cleaner.

Generally speaking, don't use arrays unless you absolutely have to; they are only rarely used in commercial code.

answered Aug 19, 2015 at 18:05

Bohemian♦

427k103 gold badges603 silver badges750 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Solocid Over a year ago

I know it might not be the best, I mean ArrayList are just perfect for almost any occasion however, I gotta learn all the corners of Java including Arrays and whatever they can and cannot do. I'm learning for my college Exam.

coderrick Over a year ago

@Bohemian could you elaborate on "how arrays are rarely used in commercial code", why is this? do you have an article I can look at to learn more?

Bohemian Over a year ago

@coderrick arrays have no "convenience" about them - you must micro-manage them. Collections on the other hand have lots of instance methods and utility method support, and they are just easier to use (not the least of which is they grow in size automatically on demand), They are virtually as fast as arrays (being backed by them), and let you get on with writing code that matters.

eric.m · Accepted Answer · 2015-08-19 18:15:46Z

2

The simple solution

public static boolean contains(String toFind, String[] strings) {
    for (String str : strings) {
        if (str.equals(toFind)) return true;
    }
    return false;
}

EDIT: To increase it after the user inputs a word, use this in the loop:

System.out.println("Enter your " + (count+1) + ": ");
words[count] = sc.next();
if (words[count].equals("ubt")) wordCount++;

edited Aug 19, 2015 at 18:15

answered Aug 19, 2015 at 17:55

eric.m

1,61212 silver badges20 bronze badges

3 Comments

Solocid Over a year ago

I'm confused here, how do I add this to my code to increase the value of wordCount, everytime the specific word is typed?

eric.m Over a year ago

Sorry, I thought you were asking for another thing xD. After words[count] = sc.next();, add 'if (words[count].equals("ubt")) wordCount++;

Solocid Over a year ago

hat scans the input however, I want to scan the array itself, after all the wanted words are typed. Which means all the input will be done and the array will be filled with elements, after that I want to scan it and find if the specific value exists, I tried this however (as suggested from @SURESH ATTA. And I think this might be exactly what I was looking for. Thanks anyways, I'll write down your code down for future personal reference.

Suresh Atta · Accepted Answer · 2015-08-19 18:17:32Z

1

You can just iterate over array

for (String str : array){
  if(str.equals("ubt")){    
   wordCount++;
 }    
}

Edit:

It's just equivalent to a normal for loop

for(int i=0; i<array.length; i++) {
    if(array[i].equals("ubt")){    
       wordCount++;
     } 
}

edited Aug 19, 2015 at 18:17

answered Aug 19, 2015 at 17:54

Suresh Atta

122k38 gold badges206 silver badges315 bronze badges

6 Comments

nanofarad Over a year ago

Aside from the typo, this doesn't have the same behavior as the OP had in their current solution.

Suresh Atta Over a year ago

Is the above code is not replacement for if(Arrays.asList(words).contains("ubt")); ?

nanofarad Over a year ago

No, it has different behavior for multiple matches within the array.

Solocid Over a year ago

What's the ' String str : array ' part do? I just want to make sure I'm not "cheating" by converting the array into an ArrayList or whatever else.

Solocid Over a year ago

Alright mate, thank you very much. This was exactly what I was looking for. Much appreciated <3

|

Collectives™ on Stack Overflow

Finding specific value inside an Array (not List)

3 Answers 3

3 Comments

3 Comments

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

3 Comments

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related