Question

How to find a number in array that appears once in PHP

Answer 1

function number_exist_few_times($arr, $number, $index) {
    for ($i = 0; $i < sizeof($arr); $i++) {
        if ($arr[$i] == $number && $i != $index) {
            return true;
        }
    }
    return false;
}
  
function get_single_number($arr) { 
    for ($i = 0; $i < sizeof($arr); $i++) {
        if (!number_exist_few_times($arr, $arr[$i], $i)) {
            return $arr[$i];
        }
    }
    return -1;
} 
    
  
$arr = array(3, 2, 1, 2, 3, 3, 1, 5, 9, 7, 7, 9, 9); 
      
echo get_single_number($arr); 
      
 
  
/*
run:
       
5
      
*/

 

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