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phplogarithm

log(1000, 100) does not return 1.5

When I run this code:

$value = log(1000, 100);

echo $value;

if ($value == 1.5) {
    echo 'Equal';
} else {
    echo 'Not Equal';
}

I see 1.5Not Equal. This is very strange because log(1000, 100) does return 1.5, but it does not match the if statement.

Why does PHP do this?

Solution

  • If you var_dump your $value you will see the result is float(1.4999999999999998) and that is not equal to 1.5, you need to use round like:

    $value = round(log(1000, 100), 1);

if ($value == 1.5) {
    echo 'Equal';
} else {
    echo 'Not Equal';
}

    Here you can see result.

    Reference: