PHP如果for循环中的条件具有浮点数[duplicate]

An if condition in a for loop would stop working after (n) times.

I'm using PHP 7.3.6-1+ubuntu18.04.1+deb.sury.org+1

Given the following code:

for($i = 0.99; $i<= 30.99; $i++){
    echo $i;
    if($i == 10.99){
        echo '<--- selected';
    }
    echo '<br>';
}

output

0.99
1.99
2.99
3.99
4.99
5.99
6.99
7.99
8.99
9.99
10.99<--- selected
11.99
12.99
13.99
14.99
15.99
16.99
17.99
18.99
19.99
20.99
21.99
22.99
23.99
24.99
25.99
26.99
27.99
28.99
29.99

This remain true when the condition is between 0.99 - 15.99, However, changing the condition between 16.99 - 29.99, <--- selected is not returned.

I ran few tests using int in my loop as shown below and it seems to work fine.

for($i = 0; $i<= 30; $i++){
    echo $i;
    if($i == 18){
        echo '<--- selected';
    }
    echo '<br>';
}

I think the problem is related to this float (0.99 - 30.99).

</div>

A possible solution is to make the numbers string and that way compare them.
Using "10.99" on one side and number_format on the other

for($i = 0.99; $i<= 30.99; $i++){
    echo $i;
    if(number_format($i,2) == "22.99"){
        echo '<--- selected';
    }
    echo "
";
}

https://3v4l.org/mvOR3

Let's clean the float before we start the comparison.

<?php
for($i = 0.99; $i<= 30.99; $i++){
    $i = number_format((float)$i, 2);
    echo $i;
    if($i == 16.99){
        echo '<--- selected';
    }
    if($i == 29.99){
        echo '<--- selected';
    }
    if($i == 10.99){
        echo '<--- selected';
    }
    echo '<br>';
}