Find occurrence of element in array in Java

Question

When the user types a value it checks if it exists in an array.

import java.util.Scanner;

public class array1 {
    public static void main(String[]args){
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter a value");
        int num = scan.nextInt();
        int [] arraynumbers = {1,2,3,4,5,6,7,8,9,10};
        for(int i = 0; i < arraynumbers.length; i++) {
            if (arraynumbers[i] == num){
                System.out.println("The value you have entered " + num + ", exists in the array");
        
            }else{
                System.out.println("The value you have entered does not exist in the array");
            }
        }
    }
}

So, when ever I type a number to test it prints:

Enter a value
3
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered 3, exists in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array
The value you have entered does not exist in the array

I am not 100% sure why this happens.

Questions

Is it because there is nothing stopping it from finishing when it finds a number in the array?
Is there a way to prevent this?

Thank you

Enter a value 3 The value you have entered does not exist in the array The value you have entered does not exist in the array The value you have entered 3, exists in the array — Jack Raiden
– Jack Raiden, Commented Feb 26, 2016 at 4:20
please mark an answer to the question or update the question — Naman
– Naman, Commented Sep 16, 2017 at 12:11

Naman · Accepted Answer · 2016-02-26 04:26:11Z

3

You are probably looking out for a break. The entire loop is traversed even if your num is found. And either of the if or else block is executed. This would help you :

if (arraynumbers[i] == num) {
    System.out.println("The value you have entered " + num + ", exists in the array");
    break;
}

and probably to avoid printing anything in case the value is not matched you can remove the else block from your code.

edited Feb 26, 2016 at 4:26

answered Feb 26, 2016 at 3:53

Naman

32.7k32 gold badges240 silver badges385 bronze badges

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

9 Comments

duffymo Over a year ago

This will still print all the values until you hit the one you've entered.

Naman Over a year ago

it would execute the else unless the value is found..which is what the OP is looking for I believe.

Naman Over a year ago

from the Q : "nothing stopping it from finishing when it finds a number in the array"

Jack Raiden Over a year ago

Hey, i tried adding this but know it says this: Enter a value 3 The value you have entered does not exist in the array The value you have entered does not exist in the array The value you have entered 3, exists in the array

Naman Over a year ago

@JackRaiden : ideally thats what we could figure out from your question the intent was? or could you specify the required output clearly in the Question please

|

Dinks · Accepted Answer · 2016-02-26 23:53:19Z

2

The break statement is definitely key. However, if you want to print whether the number is found or not, you may want to consider something like this:

int num = scan.nextInt();
int [] arraynumbers = {1,2,3,4,5,6,7,8,9,10};
String srchStr = "does not exist";

for(int i = 0; i < arraynumbers.length; i++) {
    if (arraynumbers[i] == num) {
        srchStr = "exists";
        break;
    }
}

System.out.println("The value you have entered " + num + ", " + srchStr + " in the array");

edited Feb 26, 2016 at 23:53

answered Feb 26, 2016 at 4:28

Dinks

215 bronze badges

Comments

duffymo · Accepted Answer · 2016-02-26 03:53:08Z

0

When you put that check in a loop like this, it means you check every number in the array:

for(int i = 0; i < arraynumbers.length; i++) {
}

You could do this:

List<Integer> values = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

if (values.contains(num)) {
    System.out.println("The value you have entered " + num + ", exists in the array")
} else {
    System.out.println("The value you have entered does not exist in the array");
}

answered Feb 26, 2016 at 3:53

duffymo

310k46 gold badges376 silver badges570 bronze badges

Collectives™ on Stack Overflow

Find occurrence of element in array in Java

Questions

3 Answers 3

9 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

Questions

3 Answers 3

9 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related