RegexpGarden

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let garden = "Rose\tRosemary\tPrimrose\t

Rose\tRose\tPrimrose\t

Rosemary\tRose\tRose\t

Rosemary\tRose";

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garden = garden

.replace(//gi, "Blackberry");

Lesson 35 / 42

Lesson task •

The rose should be replaced with blackberry if it is followed directly by NOT rosemary or by another rose that should be replaced

Negative Lookahead

/x(?!y)/ matches "x" only if it is not directly followed by "y"

Negative lookaheads, like Positive Lookaheads, can include nested capturing and non-capturing groups:

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console.log("foo foo foo foo 42".replace(/foo(?!(\s*foo\s*){2}42)/gi, "bar")) // bar foo bar bar 42

console.log("foo foo foo 42".replace(/foo(?!(\s*foo\s*){2}42)/gi, "bar")) // foo bar bar 42

console.log("foo foo 42".replace(/foo(?!(\s*foo\s*){2}42)/gi, "bar")) // bar bar 42

console.log("foo 42".replace(/foo(?!(\s*foo\s*){2}42)/gi, "bar")) // bar 42