String Turning to Zero

Shawazi

I am trying to parse through cities in a file to put into my database. Here is the initial piece that breaks:

for ($num=0;$num<sizeof($filearray);$num++) {
	$info = explode(",", $filearray[$num]);
	$city = $info[0];
	$province = $info[1];
	if ($city == "" || $city == 0) die("Unable to get city ($city, $info[0])<br />".$filearray[$num]);
}

It dies everytime on the first city with this output:

Unable to get city (Brooks, Brooks)
Brooks,Alberta

Somehow it is evaluating $city as 0 and triggering the die. Also, if I take away the error message, it inputs the data as 0 everytime.

Shawazi

In frustration, wondering if something about the file is messed up, I made a csv and imported the data into a table so I can parse it that way. I still had the same results with

$result = mysql_query("SELECT * FROM temp_table");
while ($info = mysql_fetch_array($result)) {
$city = $info['city'];
		$province = $info['province'];
		if ($city == "" || $city == 0) die("Unable to get city ($city, $info[0])<br />".$filearray[$num]);
}

This is the weirdest PHP problem I've ever had.

paulnaj

Hi, try using trim() ...

<?php
//...
$city = trim($info[0]);
$province = trim($info[1]); 
//...
?>

Paul.

NogDog

The expression ($city == 0) is going to evaluate as true most of the time, because when comparing a string to an integer with "==", PHP will cast the string into an integer, and a string is cast into an integer by reading it from left to right until it encounters a character which cannot be interpreted a part of a number. So if the string begins with letters (as most city names do 🙂 ), it will be evaluated as a zero.

If the goal is to make sure that something was entered, I would do as Paul suggests and trim() it, then do an identical comparison to an empty string, using the "===" operator:

$value = trim($_POST['value']);
if($value === '')
{
   // nothing was entered
}