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Java

Rafał Stasiak
Rafał Stasiak
3,763 Points
Posted by Rafał Stasiak
Rafał Stasiak
3,763 Points

Why whe need to use "not not found" instead of just "found" (!= -1 / ==1)

Hello team,

Why we need to use "not not found" instead of just "found" (!= -1 / ==1)

for example

misses.indexOf(letter) == 1 || hits.indexOf(letter) == 1 ?

Java logic requires misses.indexOf(letter) != -1 || hits.indexOf(letter) != -1 to work properly but why?

I dont get this double negation

1 Answer

Steven Parker
Steven Parker
231,210 Points
Steven Parker
Steven Parker
231,210 Points

The "not found" value is consistently -1, so it's easy to test for. But a "found" result could be any non-negative value, so it would not help to test for any specific one.

You do, however, have other options besides using the "not equals" operator:

misses.indexOf(letter) > -1 || hits.indexOf(letter) > -1   // or ">= 0"