Check for duplicate in array

Question

I have created a HTML form that passes data to Text file and text file saves data on the array.

I cannot figure out how to go about checking to see if value already exists before putting another input in the Array or text file.

     Name: <input type="text" name="name" /><br />
    Email: <input type="text" name="email" /><br />
    <input type="submit" name="save" value="Submit" /><br />
    <?php
$myArray = array();

if (isset($_POST['save']))
{
/*The file will be created in the same directory where the PHP code resides
*a+ to not overwrite text*/
$myfile = fopen("DonorList.txt", "a+") or die("Unable to open file!");
//get data entered by user from the form
fwrite($myfile, $_POST['name']);
fwrite($myfile, " ");
fwrite($myfile, $_POST['email']);
fwrite($myfile, "\r\n"); //next line
fclose($myfile);//close file

textOutput();//call function
}

print_r($myArray);
//creating function to make code more readable 
function textOutput()
{
    $lines = file('DonorList.txt');
    foreach ($lines as $lines_num => $line)
    {
        echo "User Input: ".htmlspecialchars($line)."<br />\n";
    }

    $file = fopen("DonorList.txt", "r");
    while(!feof($file))
    {
        $myArray[]= fgets($file);   
    }
    fclose($file);


}

?>

Open the file for reading. Read the values back into a different array and compare each? — jmunsch
– jmunsch, Commented Apr 14, 2015 at 19:12

Community · Accepted Answer · 2017-05-23 12:22:09Z

0

You may try after fullfilling the array

$myArray = array_unique($myArray);

Also you can check if the value is already in the array before pushing it:

while(!feof($file))
{
    $line = fgets($file);
    If (!in_array($line, $myArray)) {
        $myArray[]= $line;
    }   
}

Here you have some info about complexity: add to array if it isn't there already

edited May 23, 2017 at 12:22

CommunityBot

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answered Apr 14, 2015 at 18:12

Kevin

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1 Comment

user2102787 Over a year ago

getting Undefined variable: myArray and Warning: in_array() expects parameter 2 to be array, null given in . Still adding to the list. How can i tell user to please retry echo '<script type="text/javascript">alert("Duplicate found. Try again");</script>';?

taxicala · Accepted Answer · 2015-04-14 18:30:54Z

0

Why not call array_unique($myArray); before you use that array at the end? This will get all unique values in the array.

EDIT upon reading OP comment:

If you want to check if the value is already in the array:

$isInArray = in_array($newValue, $myArray);

edited Apr 14, 2015 at 18:30

answered Apr 14, 2015 at 18:06

taxicala

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1 Comment

user2102787 Over a year ago

when user enters the Value in HTML form and if it matches the value in array, then i want msg out saying duplicate found and to retry. something like this : echo '<script type="text/javascript">alert("Duplicate found. Try again");</script>';

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