Check if variable exist more than once in array?

Question

I want to do an if/else statement in PHP that relies on an item in the array existing more than once or not. Can you use count in in_array? to do something like:

if (count(in_array($itemno_array))) > 1 { EXECUTE CODE }

Ninja · Accepted Answer · 2012-01-16 17:13:53Z

11

Let $item be the item whose frequency you are checking for in the array, $array be the array you are searching in.

SOLUTION 1:

$array_count = array_count_values($array); 
if (array_key_exists($item, $array_count) && ($array_count["$item"] > 1))
{
   /* Execute code */
}

array_count_values() returns an array using the values of the input array as keys and their frequency in input as values (http://php.net/manual/en/function.array-count-values.php)

SOLUTION 2:

if (count(array_keys($array, $item)) > 1) 
{
     /* Execute code */
}

Check this http://www.php.net/manual/en/function.array-keys.php - "If the optional search_value is specified, then only the keys for that value are returned"

edited Jan 16, 2012 at 17:13

answered Jan 16, 2012 at 16:34

Ninja

5,1626 gold badges39 silver badges59 bronze badges

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

2 Comments

salathe Over a year ago

You might like to cater for the instance where $item does not exist in $array.

Ninja Over a year ago

I have edited and added another solution too. You may check it out.

NominSim · Accepted Answer · 2012-01-16 16:30:17Z

3

http://www.php.net/manual/en/function.array-keys.php

in_array only returns a bool, so you can't count it. array_keys however returns an array of all keys for an item in the array, so checking the length of that result will give you whether it exists more than once or not.

answered Jan 16, 2012 at 16:30

NominSim

8,5313 gold badges32 silver badges38 bronze badges

2 Comments

Ninja Over a year ago

This will not work in all cases. What if the item that repeats is not the one he is looking for?

Ninja Over a year ago

Sorry, I misunderstood what Gordon told. My bad. Realized he is talking about the search value parameter in array_keys function

jon · Accepted Answer · 2012-01-16 16:38:30Z

1

I may have misunderstood your question but maybe this is what you neeed:

if ( count($in_array) > count(array_unique($in_array)) ) 
{
 EXECUTE CODE
}

edited Jan 16, 2012 at 16:38

answered Jan 16, 2012 at 16:29

jon

6,2865 gold badges30 silver badges35 bronze badges

1 Comment

Ninja Over a year ago

This is incorrect. What if the item that repeats is not the one he is looking for?

Collectives™ on Stack Overflow

Check if variable exist more than once in array?

3 Answers 3

2 Comments

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related