Finding out if a match exists in a string

Question

I need your help,

Using javascript, how can you find out if a match is in a string?

var x = "APPLE-PEAR/BANANA and ORANGE & LEMON"

So I need a function that would allow me to check value y against value x.

the value to search for:

y = "PEAR"

if (y matches the string in x) then return true

Have you tried anything? I mean, JavaScript does have an [`includes`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes) method... — Heretic Monkey, Sep 30 '16 at 19:13
@MikeMcCaughan, [`.includes()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes) is currently a bad recommendation. It was relatively recently added to JavaScript and has [limited/no support in older browsers (e.g. IE, Opera)](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes#Browser_compatibility). In a few/several years it will be good to use. For now [`.indexOf()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/indexOf) would be a better recommendation. — Makyen, Sep 30 '16 at 19:22
@Makyen. It's a comment, not an answer. Also, that browser support link is outdated. See [this list](http://kangax.github.io/compat-table/es6/#test-String.prototype_methods_String.prototype.includes) for a more updated list. That said, my comment was mostly about having the OP try something before asking, but since they've now been awarded for their lack of research with an answer, it's a bit moot. — Heretic Monkey, Sep 30 '16 at 19:41
@MikeMcCaughan, I understand about the lack of research/own attempt issue on the part of the OP. Only thing we can do is vote down & vote/flag to close as duplicate (both are appropriate here with such an obvious lack of research). The link you provided shows IE11 as requiring a polyfill/external compiler, not as actually supported. `includes()` is not supported in the current version of IE11 (just tested to verify). — Makyen, Sep 30 '16 at 20:02

nikjohn · Accepted Answer · 2016-09-30T19:21:18.077

0

var x = "APPLE-PEAR/BANANA and ORANGE & LEMON"
y = "PEAR"
// Checks if string x having string y
if(x.includes(y)) { console.log("MATCH FOUND"); return true; }
// Returns index of string y in x , -1 if not present
if(x.indexOf(y) > -1) { console.log("MATCH FOUND"); return true; }

There are many ways of doing this. Please read the documentation for Javascript String object

edited Sep 30 '16 at 19:21

answered Sep 30 '16 at 19:13

nikjohn

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He wants it to return true so I would edit console.log to return true. – Ryan Schaefer Sep 30 '16 at 19:15
Shouldn't we leave _something_ for OP to do lol? I've updated that – nikjohn Sep 30 '16 at 19:16
`if(x.indexOf(y))` This is incorrect. The result is the position in the string, so if a string _starts_ with the search term, the returned value would be zero, which is falsey and thus won't pass the `if` check. – VLAZ Sep 30 '16 at 19:17
Not really that important I guess. – Ryan Schaefer Sep 30 '16 at 19:17

score 0 · Answer 2 · answered Sep 30 '16 at 19:13

Use String#indexOf

The indexOf() method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex. Returns -1 if the value is not found.

var x = "APPLE-PEAR/BANANA and ORANGE & LEMON",
  y = "PEAR";
console.log(x.indexOf(y) !== -1); //If true, exist

Finding out if a match exists in a string

2 Answers2