PHP：if语句中的boolean值

Question

if ($_POST) {
    $family = array("Rob", "Kirsten", "Tommy", "Ralphie");
    $isKnown = false;
    foreach ($family as $value) {
        if ($value == $_POST['name']) {
            $isKnown = true;
        }  
    }
    if ($isKnown) {
        echo "Hi there ".$_POST['name']."!";
    } else {
        echo "I don't know you.";
    }      
}

<form method="post">
    <p>What is your name?</p>
    <p><input type="text" name="name"></p>
    <p><input type="submit" value="Submit"></p>
</form>

Now isKnown = false but in the last if statement

if ($isKnown) {
     echo "Hi there ".$_POST['name']."!";
} else {
     echo "I don't know you.";
}

I can't understand it... Now $isKnown = false and it says when $isknown is false say the code that would saying when isknown is true...

I understand all code but the only thing I can't is in last if what is the value of $isKnown and how it got this value.

What the value of $isknown in this if statement: true or false?

Answer 1

The code works in the following way.If you have submitted the form,then only the value $isknown is set.If it is set, the default value of $isknown is false.

If $_POST['name'] is present in $family, then $isknown is set to true.

Now incase of if($isknown), if $isknown is true,it will echo hi there $_POST['name'] and if $unknown is false, it will echo i dont know u