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I've got a situation where I want to get a regexp from the user and run it against a few thousand input strings. In the manual I found that the RegExp object has a .compile() method which is used to speed things up ins such cases. But why do I have to pass the regexp string to it again if I already passed them in the constructor? Perhaps constructor does the compile() itself?
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compile() method is used to compile a regular expression pattern provided as a string into a regex pattern object ( re. Pattern ). Later we can use this pattern object to search for a match inside different target strings using regex methods such as a re. match() or re.search() .
JavaScript RegExp test() The test() method tests for a match in a string. If it finds a match, it returns true, otherwise it returns false.
RegExp Object A regular expression is a pattern of characters. The pattern is used to do pattern-matching "search-and-replace" functions on text. In JavaScript, a RegExp Object is a pattern with Properties and Methods.
Regular expressions are particularly useful for defining filters. Regular expressions contain a series of characters that define a pattern of text to be matched—to make a filter more specialized, or general. For example, the regular expression ^AL[.]* searches for all items beginning with AL.
The RegExp().compile() method is deprecated. It's basically the same as the constructor, which I assume is why it was deprecated. You should only have to use the constructor nowadays.
In other words, you used to be able to do this:
var regexp = new RegExp("pattern"); regexp.compile("new pattern"); But nowadays it is not any different from simply calling:
var regexp = new RegExp("pattern"); regexp = new RegExp("new pattern"); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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