PHP Calculate fee by price range - php

Question

Is anyone who can help me to create PHP and mysql Code. Here is the condition.
If price range is 1 to 20 USD, it will be show 2 USD.
If price range is 21 to 50 USD, it will be show 5 USD.
If price range is 51 to 100 USD, it will be show 7 USD.
how to do it with PHP or WordPress php coding.

Answer 1

I don't get the MySQL part here did you want to do this on the database level? or are you looking for both? anyway, in PHP it should be like this
$price = 5;
if($price >= 1 && $price <= 20){
$price = 2;
}else if($price > 20 && $price <= 50){
$price = 5;
}else if($price > 50 && $price <= 100){
$price = 7;
}
Note: you should be careful with the ranges 20.1 is greater than 20 but it is less than 21
I hope it's helpful

Answer 2

If you're using PHP 8, this would be elegantly done with match:
$fee = match(true) {
$price <= 20 => 2,
$price <= 50 => 5,
$price <= 100 => 7,
default => 0 // free shipping!
};
Since the evaluation ends when a "match arm" matches, we don't need to define the lower range -- as long as our ranges are defined in ascending order. I haven't used $price >= 1 && $price <= 20 => 2 for the first condition, assuming that $0.50 still costs something.
Since we're evaluating for the truth of expressions (true|false), a simple match($fee) wouldn't work. We need match(true) instead, where, when an expression evaluates as true, the corresponding value will be returned. Note that match must be exhaustive, ie. it must have a default condition if none of the conditions match (or you get an error).
On older PHP versions, the more long-winded switch can be used:
switch(true) {
case ($price >= 1 && $price <= 20):
$fee = 2;
break;
case $price <= 50:
$fee = 5;
break;
case $price <= 100:
$fee = 7;
break;
default:
$fee = 0;
break;
};
While switch doesn't require a default statement, it's a good idea to have a default value for transactions that exceed your ranges. Being nice, I give free shipping for orders > 100.
You can also of course use a series of if/elseif statements, but they become quite clunky if you have more than a small handful of conditions to check. match and switch exist to make cases like this more readable and easier to maintain.
Per #AhmedHassan's notes, your logic has a gap between 20/21, and 50/51. The next step from "less than or equal to 20" has to be "more than 20, less than or equal with 50". Or, if $20 flat already incurs the higher fee, then you should use >= 20 and < 50 for your price range boundaries.