Searching through arraylist?? Java

Question

Hello so I have two arraylists in my problem, one filled with the top 1000 girl names and the amount of times they're used and one filled with the top 1000 boy names and the amount of times they're used. The user inputs a name, searches through both arraylists and outputs if the name is in the top boy or girl names, what their ranking is and how many times they're used. If the name is in the top girls it also needs to output The name is not a part of the top 1000 boy names and the same if it was a boy name. This is what I have

  public void search()
  {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("Please enter the name you would like to search.");
    nameSearch = keyboard.next();

    for(int i = 0; i < girls.size(); i++)
    {
      if(nameSearch.equals(girls.get(i).getName()))
      {
        System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among girls with " + girls.get(i).getAmount() + " namings.");
      }

    }


    else
      System.out.println(nameSearch + " is not in the top 1000 girl names.");


    for(int i = 0; i < boys.size(); i++)
    {
      if(nameSearch.equals(boys.get(i).getName()))
      {
        System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among boys with " + boys.get(i).getAmount() + " namings.");
      }
    }


    else
      System.out.println(nameSearch + " is not in the top 1000 boys names.");

  }

Obviously I get an error because i can't have an else statement without an if before it.. Everything works as far as searching the array and finding the rank and whatever i just need it to output the right stuff. I am not sure at all what to do to get this to work.

update- i tried the contains method and i can never get it to work. it always outputs that it can not find the name in either arrays when i know it is a name that is there. Let me know if this looks wrong because it won't work correctly

Thanks! --Jess

   Scanner keyboard = new Scanner(System.in);
    System.out.println("Please enter the name you would like to search.");
    nameSearch = keyboard.next();

    if(girls.contains(nameSearch))
    {
      for(int i = 0; i < girls.size(); i++)
      {
        if(nameSearch.equals(girls.get(i).getName()))
        {
          System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among girls with " + girls.get(i).getAmount() + " namings.");
        }
      }
    } 
    else
      System.out.println(nameSearch + " is not in the top 1000 girl names.");



    if(boys.contains(nameSearch))
    {
      for(int i = 0; i < boys.size(); i++)
      {
        if(nameSearch.equals(boys.get(i).getName()))
        {
          System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among boys with " + boys.get(i).getAmount() + " namings.");
        }
      }
    } else
     {
      System.out.println(nameSearch + " is not in the top 1000 boys names.");
     }

Jeroen Vannevel · Accepted Answer · 2013-12-08 05:05:06Z

3

You can check if it contains it:

if(girls.contains(nameSearch)) {
   // Look for the data
} else {
   // print error
}

answered Dec 8, 2013 at 5:05

Jeroen Vannevel

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Comments

Steve P. · Accepted Answer · 2013-12-08 05:05:41Z

0

Use a boolean to determine if you went into the condition, ie:

  if(nameSearch.equals(boys.get(i).getName()))
  {
       myBoolean = true;
       //...
  }

Then use:

 if(!myBoolean)
      System.out.println(nameSearch + " is not in the top 1000 boys names.");

answered Dec 8, 2013 at 5:05

Steve P.

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Comments

chuthan20 · Accepted Answer · 2013-12-08 05:06:21Z

0

You should keep a variable to check if you have found the name or not... similar to below.

nameSearch = keyboard.next();

boolean didFindMatch=false;
for(int i = 0; i < girls.size(); i++)
{
  if(nameSearch.equals(girls.get(i).getName()))
  {
    System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among girls with " + girls.get(i).getAmount() + " namings.");
        didFindMatch=true;
        break;
  }

}


if (!didFindMatch)
  System.out.println(nameSearch + " is not in the top 1000 girl names.");

answered Dec 8, 2013 at 5:06

chuthan20

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1 Comment

Jeroen Vannevel Over a year ago

You will break after it has decided it's not in the list of girls. He also wants to search trough the list of boys.

cmd · Accepted Answer · 2013-12-08 05:09:45Z

0

To quickly search your List, you can use Collections.binarySearch(...). (see here). To use binarySearch your Collection must be sorted. The same Comparator used for sort (see here) must be used by binarySearch

You can use binarySearch to find a specified name

answered Dec 8, 2013 at 5:09

cmd

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2 Comments

Jeroen Vannevel Over a year ago

How does this answer the question?

Don Question Over a year ago

The OP is apparently not quite versed in the art of java, so i really doubt you helped him by avoiding a concrete answer!

deef0000dragon1 · Accepted Answer · 2013-12-08 05:28:48Z

0

not the cleanest but should work pretty well.

bolean inboys = false;
for(int i = 0; i < boys.size(); i++)
{
  if(nameSearch.equals(boys.get(i).getName()))
  {
    System.out.println(nameSearch + " is ranked " + (i+1) + " in popularity among boys with " +            boys.get(i).getAmount() + " namings.");
inboys = true;

  }
}

if(inboys == false)
{
  System.out.println(nameSearch + " is not in the top 1000 boys names.");
}

answered Dec 8, 2013 at 5:28

deef0000dragon1

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Comments

Syd · Accepted Answer · 2013-12-08 05:29:09Z

I think your conditions should something like these. . .

int rank = 0;
int amount = 0;

for(int i = 0; i < girls.size(); i++)
{
  if(nameSearch.equals(girls.get(i).getName()))
  {
    rank = i + 1;
    amount = girls.get(i).getAmount();
    break;
  }

}
if (rank > 0 && amount > 0) {
    System.out.println(nameSearch + " is ranked " + rank + " in popularity among girls with " + amount + " namings.");
} else {
    for(int i = 0; i < boys.size(); i++) {
       if(nameSearch.equals(boys.get(i).getName())) {
           rank = i + 1;
           amount = boys.get(i).getAmount();
           break;
       }
    }
    if (rank > 0 && amount > 0) {
        System.out.println(nameSearch + " is ranked " + rank + " in popularity among boys with " + amount + " namings.");
    } else {
        System.out.println(nameSearch + " is not in the top 1000 girl names.");
        System.out.println(nameSearch + " is not in the top 1000 boys names.");
    }
}

rabz100 · Accepted Answer · 2013-12-08 13:47:08Z

0

Seems to me you could use the arraylist.indexof method to get the index, and then if it's not -1, use the index to get the amount of times the name appears. For this to work you would need to create some sort of person object, and be able to compare it with another person an object by name.

Person p = new Person(namesearch);
int index = (girls.indexOf(p);
if(index != -1) {
   // Print info
} else {
   // print error
}

edited Dec 8, 2013 at 13:47

answered Dec 8, 2013 at 5:08

rabz100

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Comments

chaitanya89 · Accepted Answer · 2013-12-10 08:31:36Z

0

contains() method is the best you could do.

As Jeroen Vannevel mentioned,

First search the name in girls arraylist and then boys arraylist like:

if(girls.contains(nameSearch))
{
    //print your result
} else if(boys.contains(nameSearch))
{
   //print your result
} else
{
   //print not found.
}

You don't have to loop through the whole arraylist.

Java has two types of contains method

1 - boolean java.lang.String.contains(CharSequence s)

2 - public boolean contains(Object o)

In your case it's a String object, choose 2nd type of contains() and it returns true if the String is found. You could get what you wanted.

edited Dec 10, 2013 at 8:31

answered Dec 8, 2013 at 7:17

chaitanya89

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