abs

(PHP 4, PHP 5, PHP 7)

absValor absoluto

Descrição

abs ( mixed $number ) : number

Retorna o valor absoluto do number.

Parâmetros

number

O valor numérico para processar

Valor Retornado

O valor absoluto de number. Se o argumento número é do tipo float, o número retornado também é float, em outro caso será inteiro (mas poderá retornar float se o resultado tiver magnitude maior que inteiro).

Exemplos

Exemplo #1 Exemplo da abs()

<?php
echo abs(-4.2); // 4.2 (double/float)
echo abs(5);    // 5 (integer)
echo abs(-5);   // 5 (integer)
?>

Veja Também

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User Contributed Notes 2 notes

up
14
eep2004 at ukr dot net
3 years ago
<?php
$arr
= array();
for (
$i = 0; $i < 1000; $i++) $arr[] = rand(-100, 100);

$start = microtime(true);
for (
$i = 0; $i < 1000; $i++){
    foreach (
$arr as $v) $v = abs($v);
}
echo
number_format(microtime(true) - $start, 4).'<br />';

$start = microtime(true);
for (
$i = 0; $i < 1000; $i++){
    foreach (
$arr as $v) if ($v < 0) $v = abs($v);
}
echo
number_format(microtime(true) - $start, 4).'<br />';

$start = microtime(true);
for (
$i = 0; $i < 1000; $i++){
    foreach (
$arr as $v) if ($v < 0) $v *= -1;
}
echo
number_format(microtime(true) - $start, 4).'<br />';
?>
Result:
1.4061
0.9697
0.2805

Conclusion: better to check before using the feature that the number is less than zero. Even better use multiplication by -1 than this function.
up
-74
Ister
11 years ago
[*EDIT* by danbrown AT php DOT net: Merged user's corrected code with previous post content.]


jeremys indicated one thing - there is no sgn function wich actually seems a bit strange for me. Of course it is as simple as possible, but it is usefull and it is a standard math function needed occasionally.

Well, I have solved this function in a bit different matter:

<?php

function sgn($liczba)
{
    if(
$liczba>0)
       
$liczba=1;
    else if(
$liczba<0)
       
$liczba=-1;
    else if(!
is_numeric($liczba))
       
$liczba=null;
    else
       
$liczba=0;
    return
$liczba;
}

?>

The difference is that it returns null when the argument isn't a number at all.
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