Finding Duplicate values in array of integers

Question

I am beginner in Java and have recently switched to Java from C, I made this program to search for duplicate values but each time I run the program I get output as : "Duplicate value found"

My code:

public class Duplicate {

  public static void main(String[] args) {
    boolean found;
    int[] nums = { 184, 254, 123, 654, 146, 392 };
    int x, i;
    for (i = 0; i < 6; i++) {
      for (x = 1; x < 5; x++) {
        if (x != i && nums[x] == nums[i])
          found = true;
      }
    }
    if (found = true)
      System.out.println("Duplicate value found ");
    else
      System.out.println("Duplicate value not found ");
  }

}

here there is no duplicate value yet it displays the output as

Duplicate value found

which is not the case here. can you please point out my mistake here in this code?

I just need hint or correction in this code . I don't need entire program. Thank You. — Alok
– Alok, Commented Oct 21, 2015 at 13:56

Shivam · Accepted Answer · 2015-10-21 13:59:09Z

1

if(found = true) means you are assigning the true to found variable, and it will always return true. That's why it is always printing the Duplicate value found. Change it to if(found==true)

answered Oct 21, 2015 at 13:59

Shivam

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1 Comment

Alok Over a year ago

oh yes! i made the required changes and got the answer , wont repeat this mistake again. Thanx

Kotshi · Accepted Answer · 2015-10-21 13:56:31Z

0

I think that you forgot found = false on the beginning. You use = instead of == in your second if.

answered Oct 21, 2015 at 13:56

Kotshi

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4 Comments

Alok Over a year ago

i tried this public class Duplicate { 'public static void main(String[] args) { boolean found = false; int[] nums = { 184, 254, 123, 654, 184, 392 }; int x, i; for (i = 0; i < 6; i++) { for (x = 1; x < 5; x++) { if (x != i && nums[x] == nums[i]) found = true; } } if (found == true) System.out.println("Duplicate value found "); else System.out.println("Duplicate value not found "); }' } thank you sir ! :D it worked.

Kotshi Over a year ago

@Alok You're welcome, don't forget to accept the answer.

Kotshi Over a year ago

@Alok Yet, you didn't^^

Alok Over a year ago

sorry i didnt know how to . Now i did. :)

pokemzok · Accepted Answer · 2015-10-21 14:11:02Z

0

I don't know what you are trying to achieve but perhaps instead of using Array you could use Set or Map? Set doesn't allow for any duplicate values and Map doesn't allow duplicate keys.

answered Oct 21, 2015 at 14:11

pokemzok

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2 Comments

Alok Over a year ago

i will use them when i learn about them , as i said i am new to java and this site so i used all that i knew about.

Alok Over a year ago

and program worked now . with few adjustments in code

Maxim DC · Accepted Answer · 2015-10-21 14:52:45Z

0

@Kotshi i tried this

public class Duplicate {
    public static void main(String[] args) {
        boolean found = false;
        int[] nums = { 184, 254, 123, 654, 184, 392 };
        int x, i;
        for (i = 0; i < 6; i++) {
            for (x = 1; x < 5; x++) {
                if (x != i && nums[x] == nums[i])
                    found = true;
            }
        }
        if (found == true)
            System.out.println("Duplicate value found ");
        else
            System.out.println("Duplicate value not found ");
    }
}

thank you sir ! :D it worked.

edited Oct 21, 2015 at 14:52

Maxim DC

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answered Oct 21, 2015 at 13:59

Alok

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2 Comments

knut Over a year ago

Please add a comment to the answer. Don't post your comment as a answer.

Alok Over a year ago

@knut sorry didnt know. i am new here.

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