PHP 验证成本金额 2 个小数位

Question

My api requires all data related to subscription costs be in the correct format before being committed to the DB as customers will be charged the amount. The following rules apply.

1. Must be numeric with no currency symbols. Validating using is_string($data['cost'])
2. Cannot be a negative amount. Validating using $data['cost'] < 0
3. Must have two decimal places, even when the amount has no cents ($100.00).

What would be the best way to go about validating requirement #3?

Answer 1

Decided to go with something pretty straight forward. If a decimal is present in the cost, check how many places to the right. Otherwise commit to DB.

$amount = explode('.', $data['cost']);
if(isset($amount[1]) && strlen($amount[1]) > 2) {
   // response  
}

Answer 2

Use number_format() . The advantage is that no matter what you get (not enough 0s or too many 0s) it will save it in the correct format

number_format("1000000",2) // 1,000,000.00

Edit: To use this for validation,

$num = $data['cost'];
$check = number_format($num,2);
if ($num == $check) return true;