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Null Boolean Values?
Posted on 2016-08-08
Null boolean values. Can someone simplify the explanation in the photo.I understand that we can set Boolean values to false or true using mathematical calculations or string setting, but am confused as to when a Boolean would ever be "Null" or "NotNull".
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3 Comments
Active 1 day ago
In Java "bool" and "Boolean" are not quite equivalent.
"bool" is a primitive and only has 2 possible values - "true" or "false.
"Boolean" is an object and there can have 3 possible values - Boolean.TRUE, Boolean.FALSE or null.
e.g.
Boolean x = null ; // Legal
bool x = null ; // Won't compile
That being said, this warning is actually saying that they've looked at your code and figured out that "m1 is always 3".
So B5 = (m1 != 3) ; will always be false (since m1 is always 3). The null/non-null stuff isn't really coming into play in this instance - although it is good to understand them.
Hope that helps,
Doug
"bool" is a primitive and only has 2 possible values - "true" or "false.
"Boolean" is an object and there can have 3 possible values - Boolean.TRUE, Boolean.FALSE or null.
e.g.
Boolean x = null ; // Legal
bool x = null ; // Won't compile
That being said, this warning is actually saying that they've looked at your code and figured out that "m1 is always 3".
So B5 = (m1 != 3) ; will always be false (since m1 is always 3). The null/non-null stuff isn't really coming into play in this instance - although it is good to understand them.
Hope that helps,
Doug
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