如何从php中的数组中获得第一个缺失数字100

Question

hi i have created watch points in this columns 1,2,3,4,5.....100 will come

Example: 1,2,4,5,34,56,100 from above 3 is missing first this number should return

$watchPoints            =   $videoWatchedData['watch_points'];
$fetArray = explode(",",$watchPoints);  //unsorted 2,4,5,100,56,1,34

i want to sort the above one like this 1,2,4,5,34,56,100 and return first missing number.

What i have tried:

$sortFetchedArraysort   =   sort($fetArray ); //ksort,rosrt no one is working


$Expected = 1;
foreach ($sortFetchedArraysort as  $Number){
    if ($Expected != $Number)   {
        break;
    }
    $Expected++;
}
$percentageCount = $Number; // first missing number in my case output should return 3
exit;

Two problem i am facing one is sort not working second first missing number is not trturning.

Answer 1

Hope this simple one, will be helpful for you. In your post you are sorting $fetArray but there is no need, you can check it like this.

<?php

ini_set('display_errors', 1);
$array=range(1,100);//your columns

//you should sort like this, but it is not at all required
$fetArray=array(2,4,5,100,56,1,34);
sort($fetArray);

//looping over array in which we are trying to find
foreach($array as $value)
{
    //at the moment your that value is not present in array we will break from loop
    if(!in_array($value, $fetArray))
    {
        break;
    }
}
//at the moment we break from loop we will get the value which is not present
echo $value;