if and else statement mixed up - php

Question

I am doing the following if else statement below but number (//1) and number (//4) get executed at the same time, I am finding it abit hard to understand why.
<?php
//1
if($a == 1 && count($b) == 0) {
// do this
}
//2
elseif ($a == 1 && count($b) > 0) {
// do that
}
//3
if($a== 0 && count($b) == 0) {
// do a different thing
}
//4
else {
// do the last thing
}
?>
I have done this and it works but i think the should be a more suitable way for not using elseif for this.
else if($a== 0 && count($b) > 0) {
// do the last thing
}

Answer 1

but number (//1) and number (//4) get executed at the same time
It's because you don't have else before the if on //3
//3
if($a== 0 &&
Change to elseif($a== 0 &&
At the moment you have two separate IF conditions

Answer 2

You're missing a closing brace after your first if.
Also, you have a weird operator inside your first condition : $$. Maybe you intended to type &&?

Answer 3

$a = 10;
if ($a == 5) {
echo 'ok';
} elseif ($a == 10) { // $a is equal to 10, so it executes;
echo 'not_ok';
}
if ($a > 20) {
echo 'ok_ok';
} else { // $a is not >20 so else statement executes
echo 'not_not';
}
final result: not_oknot_not
If you are performing such tests on one and the same assignee, but different values, you might not want to execute more than one?
I guess you need elseif where third block is if
if ($a == 5) {
echo 'ok';
} elseif ($a == 10) { // $a is equal to 10, so it executes and stops the block;
echo 'not_ok';
} elseif ($a > 20) {
echo 'ok_ok';
} else { // $a is not >20, but the block was stopped on first elseif
echo 'not_not';
}
produces not_ok
Even if you move the else statement after the first elseif block as was suggested
if ($a > 20) {
echo 'ok_ok';
}
will execute, and if it's true, it will produce result, which again will result in double result

Answer 4

You might want to do this...
if ($a == 1 && count($b) == 0) {
// do this
}
//2
elseif ($a == 1 && count($b) > 0) {
// do that
}
elseif ($a== 0 && count($b) == 0) {
// do a different thing
}
else {
// do the last thing
}
The reason they get executed at the same time is that... Well technically they're not executed at the same time since it's procedural, but they both get executed because they are both different if else conditions. If you want only 1 execution, you should combine them :)