Question

How to print the duplicate elements of an array in PHP

Answer 1

$arr = array(3, 5, 9, 1, 7, 8, 1, 9, 0, 3, 9);   
   
for ($i = 0; $i < count($arr); $i++) {  
    for ($j = $i + 1; $j < count($arr); $j++) {  
        if ($arr[$i] == $arr[$j])  
            echo $arr[$j] . "\n";
    }  
}  


/*
run:

3
9
9
1
9

*/

 

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Answer 2

$arr = array(3, 5, 9, 1, 7, 8, 1, 9, 0, 3, 9);   

$tmp = array();

foreach ($arr as $val) {
  if (isset($tmp[$val])) {
       $tmp[$val] += 1;
  }
  else {
       $tmp[$val] = 1;
  }
}

foreach($tmp as $key => $value) {
    if ($value > 1)
        echo $key . "\n";
}




/*
run:

3
9
1

*/

 

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