ltrim negative numbers

[computermax2328]

Hello Again,

 

I have a data base that is full of averages, for example (.124). They are stored in the database like this (0.124). Of course without the parentheses on each example. I am using an equation to get these numbers and just for the record the equation is not the problem.

 

To get rid of the leading zero in (0.124) I am using ltrim. For example:

 

$num = 0.124;
ltrim($num, 0);

 

Now my equation is giving me negative numbers, which is fine. The problem is that the ltrim command is not working on the negative numbers. The number I am getting when I output is (-0.124). I want the number to be (-.124).

 

Any suggestions??

[jackr1909]

Hi,

 

first of all, using ltrim with the value of 0 might lead to problems with significant figures (remember, after the decimal point, every 0 is as important as all the other numbers, because it holds a place. Just as 0.3045 != 0.345

Here's what i would do:

 

    Find the negative numbers (preg_match maybe) and multiply them by -1 and then trim the 0 and multiply by negative one again

[jazzman1]

I don't know,it's the best way to solve this issue, but I found one few months ago.

Check out in php.net, there are lots of examples...

$num = 0.123;
print intval(strval($num*1000)); // prints 123

[Christian F.]

I'm afraid both of you are wrong. ltrim () will not alter the 0 in the middle of a number, contrary to what jackr1909 stated. Yours, jazzman1, won't do what the OP wants to do.

 

The correct solution would be to use preg_match (), like jackr1909 was alluding to. Though, not quite in the same way as he thought:

if (preg_match ('/(\\-?)0(\\.\\d+)/', $num, $matches)) {
     $num = $matches[1].$matches[2];
}

 

[jazzman1]

I want the number to be (-.124).

I'm thinking, that could be easily done, but you need to put a dot between it.

Create a new variable as string and add it a dot symbol. I don't have too much ideas about it 

// negative number
$num = 0.124;
print intval('-'.strval($num*1000)); // prints  -124

[jazzman1]

@Christian, the problem is that's invalide integer.

See your example:

 

$num = 0.123;
if (preg_match ('/(\\-?)0(\\.\\d+)/', $num, $matches)) {
     $num = $matches[1].$matches[2];
}
var_dump(intval('-'.$num));

[Pikachu2000]

The number is a decimal. What does intval() have to do with it?

[Christian F.]

Jazzman1: I think you should read the OP again, particularly this bit:

The problem is that the ltrim command is not working on the negative numbers.

 

As for whether or not my code works:

php > $num = -0.123;
php > if (preg_match ('/(\\-?)0(\\.\\d+)/', $num, $matches)) {
php { var_dump ($matches);
php { $num2 = $matches[1].$matches[2];
php { }
array(3) {
  [0]=>
  string(6) "-0.123"
  [1]=>
  string(1) "-"
  [2]=>
  string(4) ".123"
}
php > var_dump ($num2);
string(5) "-.123"
php > $num = 0.456;
php > if (preg_match ('/(\\-?)0(\\.\\d+)/', $num, $matches)) {
php { var_dump ($matches);
php { $num2 = $matches[1].$matches[2];
php { }
array(3) {
  [0]=>
  string(5) "0.456"
  [1]=>                                                                                           
  string(0) ""                                                                                    
  [2]=>                                                                                           
  string(4) ".456"                                                                                
}                                                                                                 
php > var_dump ($num2);
string(4) ".456"

Yes, I know it's an invalid float (integers are whole numbers), but that's what the OP wants.

[jazzman1]

I don't know who is wrong and who is not. I just said that this is invalid number - -.124

If the OP wants to return a string from number, why should defined $num = 0.124 as decimal, does not make any sense for me, right?

[Christian F.]

I don't know why he'd want that either, but I guess it's purely for output formatting. *Shrugs*

Trick isn't as much as making sense of why the poster would want to do something, at certain times, but what s/he's trying to do in the first place.

[Pikachu2000]

I don't know who is wrong and who is not. I just said that this is invalid number - -.124

If the OP wants to return a string from number, why should defined $num = 0.124 as decimal, does not make any sense for me, right?

 

Why is -.124 an invalid number?

 

[Christian F.]

Just tested: It isn't. Never knew that, so thanks for the heads up, Pika.

[jazzman1]

Maybe in China is a valid number

 

[Pikachu2000]

Just what, exactly, makes you think it isn't a valid number?

[jazzman1]

Hm.....you are right 

$num = -.123;
var_dump($num);

[jazzman1]

Ok, the question is, now to convert 0.123 to number -.123?

 

PS, Pika good spotting my friend 

[Christian F.]

No, the question was to change -0.123 to -.123. The OP stated that his code worked for positive numbers, but not negative. Which is what he needed help with.

[Psycho]

There's a very simple solution: str_replace()

 

Since the values are always decimals less than 1 and greater than -1, you can simply replace '0.' with '.'

 

echo str_replace('0.', '.', '0.123'); // .123
echo str_replace('0.', '.', '-0.123'); // -.123

 

Of course this would not work if there were numbers such as 10.123

[computermax2328]

I went with the str_replace(). That was the most effective method.

 

Thanks again,