Check if variables contain identical value

Question

I have problem to check either any of my variable contains identical value. Assume I have 8 variable with random generated lowercase alphabet only. For your info, this value don't need to be secure.

$variable1 = random_string();
$variable2 = random_string();
$variable3 = random_string();
$variable4 = random_string();
$variable5 = random_string();
$variable6 = random_string();
$variable7 = random_string();
$variable8 = random_string();

function random_string($length = 6) {
    $characters = 'abcdefghijklmnopqrstuvwxyz';
    $characters_length = strlen($characters);
    $random_string = '';
    for ($i = 0; $i < $length; $i++) {
        $random_string .= $characters[rand(0, $characters_length - 1)];
    }
    return $random_string;
}

I have seen this accepted answer at this question. My question, is there any simpler method to compare all this 8 variables if any of this variables have same or identical value? And if it do have same value, then regenerate another random string until none of it contain same value.

that is not right. each time page loaded new string will generated and for that you have to re-write all the css and js code again and again. Why you are doing that? — Alive to die - Anant, Nov 08 '17 at 07:54
If it is that simple - why not just append 1..8 to the 8 random generated class names? — Matschek, Nov 08 '17 at 08:00
To be precise: use `$variable1 = random_string() . "_1"` etc. — Matschek, Nov 08 '17 at 08:03

mega6382 · Answer 1 · 2017-11-08T08:37:08.907

If the number of variables is static then try:

$variable1 = random_string();
$variable2 = random_string();
$variable3 = random_string();
$variable4 = random_string();
$variable5 = random_string();
$variable6 = random_string();
$variable7 = random_string();
$variable8 = random_string();

function random_string($length = 6) {
    $characters = 'abcdefghijklmnopqrstuvwxyz';
    $characters_length = strlen($characters);
    $random_string = '';
    for ($i = 0; $i < $length; $i++) {
        $random_string .= $characters[rand(0, $characters_length - 1)];
    }
    return $random_string;
}
$arr = [];
for($i=1;$i<=8;$i++)
{
    if(!in_array(${"variable$i"}, $arr))
    {
        $arr[] = ${"variable$i"};
    }else
    {
        ${"variable$i"} = random_string();
        $i--;
    }
}

This will access all variables dynamically, and generate a new value for the var which value already exists. This works by storing all the values in an array 1 by 1, and comparing the new value with the one that already exists.

Sorry for late reply. I tried this code. It works so well. But accepted answer easily adapt to my code. Sorry and thank you for your time. — Null, Nov 09 '17 at 03:16

score 1 · Answer 2 · answered Nov 08 '17 at 08:00

How about using array_unique() and count()?

$a = array();
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());
array_push($a, random_string());

$num_dups = count($a) - count(array_unique($a));
if ($num_dups == 0) {
  echo("all unique\n");
} else {
  echo("number of dups: " . $num_dups . "\n");
}

echo("create one dup\n");
$a[1] = $a[2];

$num_dups = count($a) - count(array_unique($a));
if ($num_dups == 0) {
  echo("all unique\n");
} else {
  echo("number of dups: " . $num_dups . "\n");
}

function random_string($length = 6) {
    $characters = 'abcdefghijklmnopqrstuvwxyz';
    $characters_length = strlen($characters);
    $random_string = '';
    for ($i = 0; $i < $length; $i++) {
        $random_string .= $characters[rand(0, $characters_length - 1)];
    }
    return $random_string;
}

Output is:

$ php uniq.php
all unique
create one dup
number of dups: 1

Sorry for late reply. I tried this code. It works so well. But accepted answer easily adapt to my code. Sorry and thank you for your time. — Null, Nov 09 '17 at 03:17

Neodan · Accepted Answer · 2017-11-08T08:20:17.847

1

I think, that in this situation is better to use a one array (not eight separate variables), it's allow easily to check if generated string is not used already. With list function you can assign the data from array to separate variables.

Example:

<?php
$variables = [];
for($i = 0; $i < 8; $i++) {
    $randomString = random_string();
    if ($i > 0 && in_array($randomString, $variables))
        $i--;
    else
        $variables[$i] = $randomString;
}
list($variable1, $variable2, $variable3, $variable4, $variable5, $variable6, $variable7, $variable8) = $variables;

print_r([$variable1, $variable2, $variable3, $variable4, $variable5, $variable6, $variable7, $variable8]);

edited Nov 08 '17 at 08:20

answered Nov 08 '17 at 08:01

Neodan

5,154
2
27
38

I cannot use 1 variable. Need multiple variables. – Null Nov 08 '17 at 08:03
Sorry for late reply. I tried this code. It works so perfectly and easily adapt to my code. Thank you for your time. – Null Nov 09 '17 at 03:18

Check if variables contain identical value

3 Answers3