const regex = /(\b.+)(?=\1)/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(\\b.+)(?=\\1)', 'g')
const str = `...
bedeubedeu France The Provençal name for tripe
bee balmbee balm Bergamot
beechmastbeechmast Beech nut
beech nutbeech nut A small nut from the beech tree,
genus Fagus and Nothofagus, similar in
flavour to a hazelnut but not commonly used.
A flavoursome oil can be extracted from
them. Also called beechmast
beechwheatbeechwheat Buckwheat
beefbeef The meat of the animal known as a cow
(female) or bull (male) (NOTE: The Anglo-
saxon name ‘Ox’ is still used for some of what
were once the less desirable parts e.g. oxtail,
ox liver)
beef bourguignonnebeef bourguignonne See boeuf à la
bourguignonne
...`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions