Question 201205 in Javascript Question posted in
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Javascript & Regex: split string on an instance of text

I have a string, and a string I want to match against:

var extendedText = "the Quick Brown Fox Jumps Over the Lazy Dog"
var matchText = "the"

var regex = new RegExp(`(?=[^.*${matchText}.*$])|(?<=[^.*${matchText}.*$])`);

var splitText = extendedText.split(regex);

I want to split the string, keeping the delimiter and end up with something like this:

'the',
' quick brown fox jumps over '
'the'
' lazy dog'

The Regex above currently splits out every character however, giving me this:

'the', '', ' ', '', 'q', '', 'u', '', 'i', '', 'c',........'r', '', ' ', '' 'the', '' ' ' '' 'l', '','a'........etc etc

How can I stop the non-matching text from being split out into a list of characters and instead return a list of the substrings? Or is there a better way to do this altogether?

Tags:

2

Answers


  1. 0

    Change your regex to,

    (?=${matchText})|(?<=${matchText})

    And this will work as you desire.

    var extendedText = "the Quick Brown Fox Jumps Over the Lazy Dog"
var matchText = "the"

var regex = new RegExp(`(?=${matchText})|(?<=${matchText})`);

var splitText = extendedText.split(regex);

console.log(splitText);

    Also, if you don’t want your match text to match partially, then use b and change your regex to,

    (?=b${matchText})b|b(?<=${matchText})b

    var extendedText = "the Quick Brown Fox there Jumps Over the Lazy Dog"
var matchText = "the"

var regex = new RegExp(`(?=\b${matchText}\b)|(?<=\b${matchText}\b)`);

var splitText = extendedText.split(regex);

console.log(splitText);
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  2. 0

    Here is a split solution that uses a capture group:

    var extendedText = "the Quick Brown Fox Jumps Over the Lazy Dog";
var matchText = "the";
var arr = 
extendedText.split(new RegExp(`(\b${matchText}\b)`)).filter(Boolean);

console.log(arr);

/*[
'the',
' Quick Brown Fox Jumps Over ',
'the',
' Lazy Dog'
]*/

    filter(Boolean) has been used to filter out empty results from array.

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