Php check if any value in array is in another array

Here's a way I am doing it after researching it for a while. I wanted to make a Laravel API endpoint that checks if a field is "in use", so the important information is: 1] which DB table? 2] what DB column? and 3] is there a value in that column that matches the search terms?

Knowing this, we can construct our associative array:

$SEARCHABLE_TABLE_COLUMNS = [
    'users' => [ 'email' ],
];

Then, we can set our values that we will check:

$table = 'users';
$column = 'email';
$value = '';

Then, we can use array_key_exists[] and in_array[] with eachother to execute a one, two step combo and then act upon the truthy condition:

// step 1: check if 'users' exists as a key in `$SEARCHABLE_TABLE_COLUMNS`
if [array_key_exists[$table, $SEARCHABLE_TABLE_COLUMNS]] {

    // step 2: check if 'email' is in the array: $SEARCHABLE_TABLE_COLUMNS[$table]
    if [in_array[$column, $SEARCHABLE_TABLE_COLUMNS[$table]]] {

        // if table and column are allowed, return Boolean if value already exists
        // this will either return the first matching record or null
        $exists = DB::table[$table]->where[$column, '=', $value]->first[];

        if [$exists] return response[]->json[[ 'in_use' => true ], 200];
        return response[]->json[[ 'in_use' => false ], 200];
    }

    // if $column isn't in $SEARCHABLE_TABLE_COLUMNS[$table],
    // then we need to tell the user we can't proceed with their request
    return response[]->json[[ 'error' => 'Illegal column name: '.$column ], 400];
}

// if $table isn't a key in $SEARCHABLE_TABLE_COLUMNS,
// then we need to tell the user we can't proceed with their request
return response[]->json[[ 'error' => 'Illegal table name: '.$table ], 400];

I apologize for the Laravel-specific PHP code, but I will leave it because I think you can read it as pseudo-code. The important part is the two if statements that are executed synchronously.

array_key_exists[] and in_array[] are PHP functions.

source:

• //php.net/manual/en/function.array-key-exists.php

• //php.net/manual/en/function.in-array.php

The nice thing about the algorithm that I showed above is that you can make a REST endpoint such as GET /in-use/{table}/{column}/{value} [where table, column, and value are variables].

You could have:

$SEARCHABLE_TABLE_COLUMNS = [
    'accounts' => [ 'account_name', 'phone', 'business_email' ],
    'users' => [ 'email' ],
];

and then you could make GET requests such as:

GET /in-use/accounts/account_name/Bob's Drywall [you may need to uri encode the last part, but usually not]

GET /in-use/accounts/phone/888-555-1337

GET /in-use/users/email/

Notice also that no one can do:

GET /in-use/users/password/dogmeat1337 because password is not listed in your list of allowed columns for user.

Good luck on your journey.