Boolean issues in PHP

Question

I have a question regarding bools in php. I have a stored mysql proc that is returning a boolean. When this value is grabbed on the php side it displays the value as being a 0 or 1. This all seems fine to me and I have read in the php manual that php will interpret a 0 or 1 as false or true at compile time but this does not seem to be the case to me. I have gone a step further and casted my returned value with (bool) but this still does not seem to work.

My if statements are not properly firing because of this. Does anyone know what is going on? Thanks for the help.

Answer 1

It sounds like the boolean value is being returned as a string.

Try something like this:

$your_bool = $field_value === "0" ? false : true;

Answer 2

MySQL does not have a proper BOOL or BOOLEAN data types. They are declared as synonyms for TINYINT(1). Your procedure will return 0 or 1, which being on non-PHP ground will get transformed into a string in PHP land, so in PHP you have the strings '0' and '1'.

It is weird however that boolean casting does not convert them to the appropriate booleans. You may have some other bugs in your code.

Are you trying to cast the direct result from the query? Because that one is probably an array and:

var_dump((bool) array('0')); // true

Maybe this is your problem. Inspect the returned result.

Answer 3

I use a helpful function "to_bool" for anything I'm not sure of the type of:

function to_bool($value, $default = false)
{
    if (is_bool($value)) {
        return $value;
    }
    if (!is_scalar($value)) {
        return $default;
    }
    $value = strtolower($value);
    if (strpos(";1;t;y;yes;on;enabled;true;", ";$value;") !== false) {
        return true;
    }
    if (strpos(";0;f;n;no;off;disabled;false;null;;", ";$value;") !== false) {
        return false;
    }
    return $default;
}

Then:

if (to_bool($row['result'])) { ... }