Support negative values - php

Question

I'm in a situation where the CSV file is getting rid of the leading zero before my import and I need to be able to account for that. Let's say that I have my value as the following:
-.0982739 -> I would want all case scenarios where it's -. to turn into -0. - Here are my attempts:
if (str_contains($this->longitude, '-.')) {
$this->longitude = '0' . $this->longitude;
};
Outputs: 00-.0989070
if ($this->longitude[0] == '.') {
$this->longitude = '0' . $this->longitude;
}
Outputs: -.0989070
To simplify things, basically any . that has nothing before it, add in a 0, otherwise use the value given.
I will need it for both longitude and latitude.

Answer 1

/^([-+])?\./
The above regex matches the signs - and + if they are present and immediately followed by a .. Now, capture the matched group 1 in the regex which is ([-+])? and append 0. followed by all digits after . by taking substr of the current string.
<?php
$a = ".0982739";
if(preg_match('/^([-+])?\./',$a, $matches) === 1){
$prefix = $matches[1] ?? '';
$a = $prefix . '0.' . substr($a,$prefix == '' ? 1 : 2);
}
echo $a;

Answer 2

Try this :
<?php
$x = -.54321 ;
echo $x . "\r\n" ;
$x = "-.12345" ;
echo $x . "\r\n" ;
echo floatval($x) . "\r\n" ;
echo sprintf("%0.5f", $x) ;
?>
I assume your CSV is returning only string values, because as soon as I echo a "native" float, the echo is just fine.
As soon as your float is correctly formatted, you can catch it in a string value if needed.

Answer 3

You could use str_replace:
$this->longitude = ltrim($this->longitude, '+');// remove leading +
if ($this->longitude[0]=='.' || substr($this->longitude, 0, 2)=='-.')) {
$this->longitude = str_replace('.', '0.', $this->longitude);
}
The if condition matches any string that begins with '.' or '-.' And if so, str_replace replaces the . with 0.

Answer 4

`$var = 0.0989070;
$neg = -$var; // easiest
$neg = -1 * $var; // bit more explicit
$neg = 0 - $var; // another version`

Answer 5

You could check for numbers before dot....
<?php
if (str_contains($this->longitude, '.')) {
$beforedot = strstr($this->longitude,'.',true); //Get anything before
if (is_numeric($beforedot)) { echo "do nothing"; } //check if is number do nothing
else {
$this->longitude = str_replace('.', '0.', $this->longitude); //else do replace . with 0.
}
};
?>

Answer 6

I created a class and assigned -.0982739 to a property called $longitude. In the constructor I did echo $this->longitude and it came out as -0.0982739 which I believe is exactly as you want it to be. I couldn't manage to reproduce it.
<?php
class Test
{
private $longitude = -.0982739;
public function __construct()
{
}
public function test()
{
echo $this->longitude;
}
}
<?php
include "Test.php";
$test = new Test();
$test->test();