log(1000, 100) does not return 1.5-CodePudding

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?

CodePudding user response：

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: