如何检查字符串数组中是否存在字符串

I have data stored in a string: such as $string='12';
'12' represents 2 pieces of data, 1 and 2

In 3 columns, I have those same ids stored, the array comes out as :

ex1: $array= ('num1' => 1, 'num2' => 2, 'num3' => )
ex2: $array= ('num1' => 5, 'num2' => 4, 'num3' => 3)

How could I compare these and return true if the numbers exist in both places?

For instance: using the above example: for ex1: 12 would return TRUE

34 would return FALSE for ex2: 345 would return TRUE

This works, please see results below: (Value must be present in both array to return true.

  $result = true;
    $string1 = '43';
    $string = str_split($string1);
    $example1 = array('num1' => 1, 'num2' => 2, 'num3' => 3,  'num4' => 4, 'num5' => 5);
    $example2 = array('num1' => 5, 'num2' => 4, 'num3' => 3);
    foreach ($string as $st) {
        if((in_array($st, $example1) && in_array($st, $example2))  && $result == true){
            $result = true; //true
        } else {
            $result = false;
        }
    }
    if($result == true){
            echo 1; //true
        } else {
            echo 0; //false
        }
    exit;
    //Test Results:
    //$string1 = '12'; //result 0
    //$string1 = '34'; //result 1
    //$string1 = '55'; //result 1
    //$string1 = '43'; //result 1

try this: You can use array_intersect().

$string = '12';

//split string into array of characters
$arr = str_split($string);

//testing columns
$compare1 = array('num1' => 1, 'num2' => 2, 'num3' => '');
$compare2 = array('num1' => 5, 'num2' => 4, 'num3' => 3);

//returns an array containing all the values of $arr inside $compare1
$int1 = array_intersect($arr, $compare1);

//returns an array containing all the values of $arr inside $compare2
$int2 = array_intersect($arr, $compare2);

//if $arr contents are in $compare1 return true, otherwise false
echo ! empty($int1);

//if $arr contents are in $compare2 return true, otherwise false
echo ! empty($int2);

try in_array() function http://php.net/manual/en/function.in-array.php

but I don't understand why 345 would return true

I'm late to the party... but I had already started, so might as well! Here's my solution:

function yayOrNay($array, $string) {

    $stringArray = str_split($string);

    $arrayDiff = array_diff($stringArray, array_values($array));

    return empty($arrayDiff);
}

LIVE DEMO