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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Useful Array Methods

whats the difference between inStock.indexOf(search) < -1 and inStock.indexOf(search) !== -1 ?

as the title says, I tried the program with if ( inStock.indexOf(search) !== -1 ) and if ( inStock.indexOf(search) < -1 ) and the reslt seems to be the same. my question is why to opt for one rather than the other.

thank you in advance ^^

2 Answers

Steven Parker
Steven Parker
229,644 Points

I'm surprised the difference wasn't noticeable. The value of "indexOf" should never be less than -1, so the test for "< -1" should never be true.

On the other hand, if an index is found, the method will return the index number of the match, which will be a non-negative integer. So testing for "!== -1" should be true anytime a match is found.

For future use, the "includes" method can do the same job as the latter but without the comparison. For example: "inStock.includes(search)". The result is true when a match is found.

what about the "find" method?

I tried "inStock.find(search)" but had no success...

Steven Parker
Steven Parker
229,644 Points

The "find" method syntax requires a callback function (instead of a string) as the argument.

I understand thank you very much ^^