is_numeric not returning true for 0 in form data

[edpatterson]

I have a form with a dynamically created table, one of the cells is a text field. The cell name is 'item-' with a numeric value appended (item-1, item-2,...,item-87). Not all of the cells will contain a value, all values are supposed to be integers, through no more that 99999. I thought I could simply step through the $_POST data and only process the elements that had a value. Works just fine as long as I don't enter a 0. Problem is 0 is a valid entry.

 

item-18 has a value of 0 but a update line is not being created.

 

What I don't get is at the bottom the is_numeric(0) returns true (1).

 

Here is my output, code I am using follows

 

item-1 is the key 1 is the value

update items set itemCount = 1 where itemID=1

item-5 is the key 3 is the value

update items set itemCount = 3 where itemID=5

item-6 is the key 5 is the value

update items set itemCount = 5 where itemID=6

item-7 is the key 7 is the value

update items set itemCount = 7 where itemID=7

item-11 is the key 9 is the value

update items set itemCount = 9 where itemID=11

item-12 is the key 2 is the value

update items set itemCount = 2 where itemID=12

item-13 is the key 4 is the value

update items set itemCount = 4 where itemID=13

item-16 is the key 6 is the value

update items set itemCount = 6 where itemID=16

item-17 is the key 8 is the value

update items set itemCount = 8 where itemID=17

item-18 is the key 0 is the value

item-19 is the key is the value

...

0

1

 

<?php
  if(is_array($_POST)){
    foreach($_POST as $key => $value){
      echo $key.' is the key '.$value.' is the value<br />';
      if((isset($key)) && (!$value == '')){
        if(is_numeric($value)) {
          // echo $value.' is a number<br />'."\n";
          $arrItems = explode("-",$key);
          echo 'update items set itemCount = '.$value.' where itemID='.$arrItems[1]."<br />\n";
        }
      }
    }
  } else {
    echo '$_POST is not an array....';
  }
  echo $_POST["item-18"]."<br />\n";
  echo is_numeric(0)."<br />\n";
?>

[Alex]

0 is different from "0" (string). Any data from a form will be a string.

 

Instead of is_numeric which checks the datatype of the argument, you're looking for ctype_digit.

 

I confused functions, nevermind. Solution in my next post..

[edpatterson]

Sigh, nope, same thing. Cells with a 0 in them do not generate an update line.

In my own defense, the reason I used is_numeric is from the manual

Note:

To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

I must have read it bass ackwards. I thought it meant I had to use is_numeric instead of is_int. In either case 0's are still not working.

 

Ed

[Alex]

Sorry, I confused functions.

 

The reason your code isn't working isn't because of the is_numeric() part at all, that's correct. The issue is here:

 

if((isset($key)) && (!$value == '')){

 

namely the (!$value == '') portion. If $value == 0, then that statement will evaluate to false because 0 is evaluated to false, and !false == '' (or true == '') is false. Instead use:

 

if((isset($key)) && $value != ""){

 

Alternatively, you could use:

 

if((isset($key)) && !($value == '')){

 

Notice the position of the ! operator.

[edpatterson]

Thanks a bazilion! It was driving me nuts.

[Pikachu2000]

Keep in mind also that is_numeric will return TRUE for more than just decimal integers. 12E839 and 0xF3B24 would both be accepted as valid input . . .