Switch statement unusual behaviour - php

Question

echo get_option('bp-username-field'); and echo get_option('bp-email-field'); respectively outputs checked and 0. but with this code both the cases are running. i.e. both hello from username and hello from email are dispayed.
switch("checked")
{
case get_option('bp-username-field'):
echo 'hello from username';
case get_option('bp-email-field'):
echo 'hello from email';
...
}
And if i change switch("0") it only echoes hello from email. Also, with swith(0) both case are running. What is this behaviour?

Answer 1

You have to add a break after the case. If not all cases will be executed. That is normal behavior for switch Statements
switch("checked")
{
case get_option('bp-username-field'):
echo 'hello from username';
break;
case get_option('bp-email-field'):
echo 'hello from email';
...
}

Answer 2

You are probably missing break
switch("checked")
{
case get_option('bp-username-field'):
echo 'hello from username';
break;
case get_option('bp-email-field'):
echo 'hello from email';
break;
...
}
When the first case gets executed, then you need to break the switch. You need to introduce break to break execution of rest of the cases that follows the selected case.
When switch(0) was called, it is the final case (as of here), so it doesn't execute the one before the second case.

Answer 3

switch/case does loose comparison. That's mean that "checked" == 0 is true. What you want to do is:
switch(true)
{
case get_option('bp-username-field') === "checked":
echo 'hello from username';
case get_option('bp-email-field') === "checked":
echo 'hello from email';
...
}
But in a switch statement, the condition is evaluated only once and the result is compared to each case statement. This mean that after the first case is evaluate as true, all the other case will be executed until the end of the switch. What you really want it:
if (get_option('bp-username-field') === "checked") {
echo 'hello from username';
}
if (get_option('bp-email-field') === "checked") {
echo 'hello from email';
}

Answer 4

Because your statement is wrong;
you should compare the variable what ever it is inside switch(variable) to all those cases. for example.
$favcolor = "red";
switch ($favcolor) {
case "red":
echo "Your favorite color is red!";
break;
case "blue":
echo "Your favorite color is blue!";
break;
case "green":
echo "Your favorite color is green!";
break;
default:
echo "Your favorite color is neither red, blue, nor green!";
}