PHP：变量是int但不能执行计算

Question

$bal = (int)$balance;
echo is_int($bal);

$balance is from a file_get_contents($webservice);

I am using (int) to convert a string to integer. is_int returns 1 for true as verification.

Because the value of $bal is always negative, I do the following calculation to make it a positive:

$bal = $bal * -1;

When I do this, the value becomes 0 even though $bal may be -150 previously.

EDIT 1 var_dump ($balance) is returning: string(110) " -399.6000"

EDIT 2 I have used XML Parser to assign variable to array - see my answer below.

Answer 1

The issue is that I was using file_get_contents to interact with a GET method for a Web Service.

This was returning XML header data which I overlooked when assigning to a variable.

To clear out the XML to leave me with just the value I wanted, I used the PHP XML_PARSER which stored file_get_contents into an array and allowed me to assign the array value to an integer.

$result = file_get_contents($base);

$p = xml_parser_create();
xml_parse_into_struct($p, $result, $vals, $index);
xml_parser_free($p);  
$bal = $vals[0]['value'];
echo $bal *-1;