PHP - show only duplicate values from array without builtin function

Show only duplicate values from array without built in function

$arr = array(3,5,2,5,3,9);
I want to show only common elements i.e 3,5 as output.

Answer1:

The logic here is simple:

I am not a php developer so i am using c++ to explain this method !

int Array[6]= {3,5,2,5,3,9};

//create a for-loop for ArrayA

    for(int i=0; i<6; i++)
    {

//create a for-loop for checking element from ArrayA is equal to any other element


        for(int s=0; s<6; s++)
        {



// to check if terms are equal (note i!=s)

            if(Array[i]==Array[s] && i!=s)
            {

             //Print Array elements or store it in another array and the use any unique array function to see unique elements !
            }
        }
    }

Try to make the code for php yourself !

Answer 2:

How about something outside of the box:

$array = array(3, 5, 2, 5, 3, 9);
$duplicates = array_duplicates($array);

function array_duplicates(array $array)
{
    return array_diff_assoc($array, array_unique($array));
}

Answer 3:

Finally got there:

<?php

$arr = array(3,5,2,5,3,9);
$temp_array = array();

foreach($arr as $val)
{
    if(isset($temp_array[$val]))
    {
        $temp_array[$val] = $val;
    }else{
        $temp_array[$val] = 0;
    }
}

foreach($temp_array as $val2)
{
    if($val2 > 0)
    {
        echo $val2 . ', ';
    }
}

?>

I doubt it will work for words, or characters, for this you will have to manipulate the array_keys.

Output:

3, 5,

Answer 4:

1. function hasDuplicate($array) {
2. $defarray = array();
3. $filterarray = array();
4. foreach($array as $val){
5. if (isset($defarray[$val])) {
6. $filterarray[] = $val;
7. }
8. $defarray[$val] = $val;
9. }
10. return $filterarray;
11. }

Answer 5:

1. $arr = array(3,5,2,5,3,9);
2. foreach($arr as $key => $val){
3. //remove the item from the array in order
4. //to prevent printing duplicates twice
5. unset($arr[$key]);
6. //now if another copy of this key still exists in the array
7. //print it since it's a dup
8. if (in_array($val,$arr)){
9. echo $val . " ";
10. }
11. }