PHP if / else问题使用true / false

Question

My code looks like this:

$muted = 'true'; //Note this is only for testing
if ($muted == 'false' || $muted == '' || $do_not_text == '' || $do_not_text =='false'){
//do this first thing
}
else{
//do something else
}

I can't get my else to run. What syntax am I messing up?

Related to this, I'm storing a value in my database (that will be what's called to set $muted in my real code) that's either 'true', 'false', or ''. What data type should I be storing these as? Currently, I'm using VARCHAR , but I suspect this is all part of the problem.

Answer 1

$do_not_text == '' evaluates to true. Why? Because $do_not_text is not defined which is a falsy value. You are comparing it to an empty string which also equates to a falsy value. So that comparison is true causing the first if statement to be evaluated as true.

Answer 2

I'm not sure why you're using strings for what should be boolean values.

$muted = true; // no need for quotes

You might also consider using the === operator when comparing boolean values.

if ($muted === false || // etc...

What data type should I be storing these as?

Boolean values in MySQL are typically stored as 1 or 0.

field_name TINYINT(1) UNSIGNED NOT NULL DEFAULT 0

Answer 3

Store them as TINYINT with length of 1 because its only 1 and 0, and 0 as the default value.

Then you can make $muted = boolval($db_muted_val); if you want, or use $db_muted_val as is, because 1 is true and 0 is false .

if ($db_muted_val) {
    // do this first thing
} else {
    // do something else
}