PHP regular expression in action: matching prices

When shopping online, we often encounter situations where we need to filter prices. At this time, we need to use regular expressions to match prices. This article will teach you how to use PHP regular expressions to implement the price matching function.

First, we need to understand the characteristics of the price we want to match. Generally speaking, the price format is divided into the following types:

1. Integer price, such as 99 yuan, 1,000 yuan, etc.
2. Price with decimal point, such as 99.99 yuan, 888.88 yuan, etc.
3. Price with decimal point and unit, such as 99.99 yuan/bottle, 666.66 yuan/piece, etc.

Next, we can match these prices through regular expressions.

For the first integer price, we can use the following regular expression to match:

preg_match("/d+元/", $str, $match);

Among them, d represents matching numbers, represents matching numbers one or more times, and yuan represents matching "yuan" "Character. $str is the string to be matched, $match is the matching result.

For the second type of price with a decimal point, we can use the following regular expression to match:

preg_match("/d+.d+元/", $str, $match);

Among them, .d means matching decimal points and numbers, and you need to add d in front to Guaranteed to match numbers before the decimal point. $str is the string to be matched, $match is the matching result.

For the third type of price with decimal point and unit, we can use the following regular expression to match:

preg_match("/d+.d+元/.*/", $str, $match);

Among them, d.d means matching the numbers before and after the decimal point, / means matching the slant Slash, .* means matching any character after the slash. $str is the string to be matched, $match is the matching result.

It should be noted that in actual applications, we may encounter situations where the price of the same product is in different units, such as "99.99 yuan/bottle" and "999.99 yuan/box". At this time, we can use the "|" symbol in regular expressions to match multiple options. For example:

preg_match("/d+.d+元/(瓶|箱)/", $str, $match);

The "|" symbol indicates selecting a match between "bottle" and "box". $str is the string to be matched, $match is the matching result.

By matching the above regular expressions, we can easily filter and extract prices.

Finally, it needs to be reminded that although regular expressions are powerful, they are also complex and error-prone. Therefore, in actual application, we need to carefully debug and test regular expressions to ensure that we can accurately match the results we need.

I hope this article can help everyone better master the application of PHP regular expressions, so that we can easily find the products we like when shopping online!

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