php strlen validation with user inputting at least 16 digits

Question

I am attempting to validate a credit card number input to be at least 16 numbers. My code doesn't seem to work. I don't feel too confident about my syntax. Any help?... thanks.

<form name="ccard" action="validate.php" method=post>
CC Type
<select name="cc_type">
<option value="mc">Master Card</option>
<option value="visa">Visa</option>
</select><br>
Creditcard number:
<input type=number name="ccard_num" value="num"><br>
Exp Year:
<input><br>
Exp Month:
<input>
</form>

php code

<?php
$cc_length = $_POST['ccard_num'];

if (strlen( $cc_length == 15) {
echo "Valid";
}
elseif (strlen($cc_length != 15) {
echo "Invalid entry";
}
?>

The error is obvious and if you had error reporting turned on PHP would tell you exactly what is wrong. — John Conde, Oct 04 '15 at 15:14
RTM on strlen http://php.net/manual/en/function.strlen.php your answer's in there ;-) — Funk Forty Niner, Oct 04 '15 at 15:16
You should also check if it is numeric. If you expect numbers. Use `filter_input` or `filter_input_array` — Elias Nicolas, Oct 04 '15 at 15:19

score 1 · Answer 1 · answered Oct 04 '15 at 15:16

strlen returns the length of a string. You need to compare the return value of this function. Right now you comparen the string value to a number and then pass this boolean value to the strlenfunction. Change your code to:

<?php
$cc_length = $_POST['ccard_num'];

    if ( strlen($cc_length) == 15 ) {
    echo "Valid";
}
    elseif ( strlen($cc_length) != 15 ) {
    echo "Invalid entry";
}
?>

score -1 · Answer 2 · answered Oct 04 '15 at 15:16

-1

Your IF condition, no closing parenthesis, its very obvious.

answered Oct 04 '15 at 15:16

user1149244

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php strlen validation with user inputting at least 16 digits

2 Answers2