Make sure password contains at least one character from 3 arrays - php

Question

How do I make sure that the password contains at least one character from each array? I could use do..while, right? What I don't quite understand is what I will need to put in the if statement inside do...while.
Is do...while the only way to ensure at least one character from each array is in the final password or are there other ways?
$length = 6;
$a1 = str_split('0123456789');
$a2 = str_split('%^*+~?!');
$a3 = str_split('abcdefghigklmnopqrstuvwxyz');
$result = ""; //final random password
for($i = 0; $i < $length; $i++){
$values = [$a1,$a2,$a3];
$chosen = array_rand($values);
$result .= $values[$chosen][array_rand($values[$chosen])];
}
echo $result;

Answer 1

$length = 6;
$a1 = str_split('0123456789');
$a2 = str_split('%^*+~?!');
$a3 = str_split('abcdefghigklmnopqrstuvwxyz');
$resultArr[] = $a1[array_rand($a1)];
$resultArr[] = $a2[array_rand($a2)];
$resultArr[] = $a3[array_rand($a3)];
for($i = 0; $i < $length-3; $i++){
$values = [$a1,$a2,$a3];
$chosen = array_rand($values);
$resultArr[] = $values[$chosen][array_rand($values[$chosen])];
}
shuffle($resultArr);
$result = implode($resultArr); //final random password
echo $result;

Answer 2

You can surround the for wit ha do..while and in the condition check with preg_match() and a regex pattern that checks if at least one character is in the result:
<?php
$length = 6;
$a1 = str_split('0123456789');
$a2 = str_split('%^*+~?!');
$a3 = str_split('abcdefghigklmnopqrstuvwxyz');
$result = ""; //final random password
do {
for($i = 0; $i < $length; $i++){
$values = [$a1,$a2,$a3];
$chosen = array_rand($values);
$result .= $values[$chosen][array_rand($values[$chosen])];
}
} while(!(preg_match('/^(?=.*?[0-9])(?=.*?[a-z])(?=.*?[%*+?!]).{1,}/', $result)));
echo $result;
If the there's no coincidences with the pattern using preg_match, then will return false, in the do..while condition we check if one preg_match is false, if it is, do it again.

Answer 3

I made my answer general for any number of arrays.
I would use preg_match() for this, but for the question you asked, yes, you need to check each array separately:
$user_inputted_password = $_POST['user_inputted_password'];
$length = strlen($user_inputted_password); // user input password - you are capturing this somewhere, right
$a1 = str_split('0123456789');
$a2 = str_split('%^*+~?!');
$a3 = str_split('abcdefghigklmnopqrstuvwxyz');
$validate = array();
$result = ""; //final random password
function populate_validation_array($match_num, &$validate) {
if (!in_array($match_num, $validate)) {
$validate[] = $match_num;
}
}
$numeric_indexes = array(1, 2, 3);
$index_count = count($numeric_indexes);
for($i = 0; $i < $length; $i++){
for($j = 0; $j < $index_count; $j++) {
$numeric_index = $numeric_indexes[$j];
if (in_array($user_inputted_password[$i], ${"a" . $numeric_index})) {
populate_validation_array($numeric_index, $validate);
}
}
}
if (count($validate) === $index_count) {
$values = array();
for($i = 0; $i < $index_count; $i++) {
$values[] = ${"a" . ($i + 1)};
}
$chosen = array_rand($values);
$result .= $values[$chosen][array_rand($values[$chosen])];
}
echo $result;