PHP: Variable is int but can't perform calculation

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.

This isn't the answer, but why not use abs() instead of multiply be -1. Someday $bal may not always be negative. — Jason McCreary
– Jason McCreary, Commented Oct 18, 2010 at 12:07
Although you should indeed use abs, there is nothing wrong with the provided code, and if $bal==-150 & -1==-1, it will not give you 0. More likely, there is some garbage in $balance (currency signs, HTML tags, whitespace etc.) which prevents it from being cast to the desired INT. Normal handling would cast it to 0 if it cannot recognize a number. — Wrikken
– Wrikken, Commented Oct 18, 2010 at 12:13
@baswoni: string(110) " -399.6000" does not compute, if you're looking in a browser, please look at the source, not the webpage, as -399.6000 has far less then 110 characters. — Wrikken
– Wrikken, Commented Oct 18, 2010 at 12:20

jwueller · Accepted Answer · 2010-10-18 13:17:59Z

3

I recommend PHP's abs()-function if you want to make sure that you are always dealing with a positive number:

$bal = abs($bal);

edited Oct 18, 2010 at 13:17

answered Oct 18, 2010 at 12:07

jwueller

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4 Comments

thisisready Over a year ago

I get a return of 0 when I do this.

thisisready Over a year ago

The issue is that I've got bad data. var_dump ($balance) = string(110) " -399.6000"

jwueller Over a year ago

@baswoni: What happens if you use intval() (probably in connection with trim())?

oezi Over a year ago

you missed the $-sign in the abs-call ;) / @baswoni: you should have noticed his fault if you don't just copy&paste...

janmoesen · Accepted Answer · 2010-10-18 12:19:30Z

2

As per your var_dump output, your string begins with a space. Use this:

$bal = intval(trim($balance));

answered Oct 18, 2010 at 12:19

janmoesen

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2 Comments

Wrikken Over a year ago

More then a space, a space is not accounting for the other 100 missing characters :)

janmoesen Over a year ago

@Wrikken: right you are! I'm guessing his reaction was: "Oh, they don't need to see all of this junk; I'll just leave that out."

thisisready · Accepted Answer · 2010-10-18 12:32:06Z

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;

answered Oct 18, 2010 at 12:32

thisisready

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Comments

Community · Accepted Answer · 2023-11-17 19:32:19Z

0

try this to if you want to revert the sign:

$bal = $bal * (-1);

or use abs() if you want it to be always positive:

$bal = abs($bal);

edited Nov 17, 2023 at 19:32

CommunityBot

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answered Oct 18, 2010 at 12:06

oezi

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Comments

Ruel · Accepted Answer · 2010-10-18 12:07:57Z

0

$bal = abs($bal);

http://php.net/manual/en/function.abs.php

answered Oct 18, 2010 at 12:07

Ruel

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Comments

Grumpy · Accepted Answer · 2010-10-18 12:08:23Z

0

$balance="-150";
$bal = $balance*1;
echo $bal;

gives -150

answered Oct 18, 2010 at 12:08

Grumpy

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1 Comment

oezi Over a year ago

... and has nothing to do with the question - thats about multiplying by -1.

twon33 · Accepted Answer · 2010-10-18 12:14:27Z

0

What is your program doing with $bal after you do the multiply? The following PHP script worked as expected on my laptop:

<?php
$balance = "-150";
$bal = (int)$balance;
echo is_int($bal);
$bal = $bal * -1;
echo $bal;
?>

Output is "1150" because I didn't bother with linebreaks. Can you post any more of your code

answered Oct 18, 2010 at 12:14

twon33

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blahdiblah · Accepted Answer · 2011-09-02 19:18:08Z

0

I think you can make your calculations easy by using the function intval() which returns the integer value of any variable. Go through the function description if you have a php manual.

edited Sep 2, 2011 at 19:18

blahdiblah

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answered Oct 18, 2010 at 12:13

Prateek

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1 Comment

Wrikken Over a year ago

(int)$var & intval($var) are equivalents.

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