Regular expressions Capture Groups help to understand

can someone help me to understand how \1\1 works here?

let repeatRegex = /(\w+) \1 \1/;   <-------- how this works ?

Link to the challenge:

the parentheses in regular expression define a capture group, expression in the parentheses match characters and you can capture the matched characters by numbers starting from 1 preceding them by backslash. if there had been two capture groups e.g. /(\w+)(\d+)/ then you can access the first one by \1, and second one by \2. you can learn and practice regex online at

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