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9-regular-expressions/17-regexp-methods
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`‎9-regular-expressions/17-regexp-methods/article.md‎`

Lines changed: 5 additions & 15 deletions

Original file line number	Diff line number	Diff line change
`@@ -316,7 +316,7 @@ alert( !/love/i/!.test(str) ); // false`
`316`	`316`	`alert( str.search(!/love/i/!) != -1 ); // false`
`317`	`317`	```
`318`	`318`
`319`		-If the regexp has flag `pattern:g`, then `regexp.test` looks from `regexp.lastIndex` property and updates it, just like `regexp.exec`.
	`319`	+If the regexp has flag `pattern:g`, then `regexp.test` looks from `regexp.lastIndex` property and updates this property, just like `regexp.exec`.
`320`	`320`
`321`	`321`	`So we can use it to search from a given position:`
`322`	`322`
`@@ -326,13 +326,11 @@ let regexp = /love/gi;`
`326`	`326`	`let str = "I love JavaScript";`
`327`	`327`
`328`	`328`	`// start the search from position 10:`
`329`		`-regexp.lastIndex = 10`
	`329`	`+regexp.lastIndex = 10;`
`330`	`330`	`alert( regexp.test(str) ); // false (no match)`
`331`	`331`	```
`332`	`332`
`333`		`-`
`334`		`-`
`335`		-````warn header="Same global regexp tested repeatedly may fail to match"
	`333`	+````warn header="Same global regexp tested repeatedly on different sources may fail"
`336`	`334`	If we apply the same global regexp to different inputs, it may lead to wrong result, because `regexp.test` call advances `regexp.lastIndex` property, so the search in another string may start from non-zero position.
`337`	`335`
`338`	`336`	For instance, here we call `regexp.test` twice on the same text, and the second time fails:
`@@ -344,15 +342,7 @@ alert( regexp.test("javascript") ); // true (regexp.lastIndex=10 now)`
`344`	`342`	`alert( regexp.test("javascript") ); // false`
`345`	`343`	```
`346`	`344`
`347`		-That's exactly because `regexp.lastIndex` is non-zero on the second test.
	`345`	+That's exactly because `regexp.lastIndex` is non-zero in the second test.
`348`	`346`
`349`		-To work around that, one could use non-global regexps or re-adjust `regexp.lastIndex=0` before a new search.
	`347`	+To work around that, we can set `regexp.lastIndex=0` before each search. Or instead of calling methods on regexp, use string methods `str.match/search/...`, they don't use `lastIndex`.
`350`	`348`	````
`351`		`-`
`352`		`-## Summary`
`353`		`-`
`354`		`-There's a variety of many methods on both regexps and strings.`
`355`		`-`
`356`		`-Their abilities and methods overlap quite a bit, we can do the same by different calls. Sometimes that may cause confusion when starting to learn the language.`
`357`		`-`
`358`		`-Then please refer to the recipes at the beginning of this chapter, as they provide solutions for the majority of regexp-related tasks.`

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