How do I negate this logical expression?
So, right now my code has something like this:
if(DateA <= utcNow || (DateA == null && DateB <= utcNow)) doSomething();
I want to do something like this now:
if(!InitialExpression) continue;
AFAIK, if A || B, the negation would be !A && !B.
But this doesn't work: if(DateA > utcNow && (DateA != null || DateB > utcNow)) continue;.
When DateA = null and DateB > utcNow it should fall into the continue but it doesn't.
Edit:
My mistake was assuming the opposite of DateA <= utcNow is DateA > utcNow. But it's DateA == null || DateA > utcNow
logic logical-operators boolean-logic
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
add a comment |
So, right now my code has something like this:
if(DateA <= utcNow || (DateA == null && DateB <= utcNow)) doSomething();
I want to do something like this now:
if(!InitialExpression) continue;
AFAIK, if A || B, the negation would be !A && !B.
But this doesn't work: if(DateA > utcNow && (DateA != null || DateB > utcNow)) continue;.
When DateA = null and DateB > utcNow it should fall into the continue but it doesn't.
Edit:
My mistake was assuming the opposite of DateA <= utcNow is DateA > utcNow. But it's DateA == null || DateA > utcNow
logic logical-operators boolean-logic
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
Are you looking forelse? As inif (thiscondition) dothis else dothat?
– Ken White
Nov 14 '18 at 3:50
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16
add a comment |
So, right now my code has something like this:
if(DateA <= utcNow || (DateA == null && DateB <= utcNow)) doSomething();
I want to do something like this now:
if(!InitialExpression) continue;
AFAIK, if A || B, the negation would be !A && !B.
But this doesn't work: if(DateA > utcNow && (DateA != null || DateB > utcNow)) continue;.
When DateA = null and DateB > utcNow it should fall into the continue but it doesn't.
Edit:
My mistake was assuming the opposite of DateA <= utcNow is DateA > utcNow. But it's DateA == null || DateA > utcNow
logic logical-operators boolean-logic
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
So, right now my code has something like this:
if(DateA <= utcNow || (DateA == null && DateB <= utcNow)) doSomething();
I want to do something like this now:
if(!InitialExpression) continue;
AFAIK, if A || B, the negation would be !A && !B.
But this doesn't work: if(DateA > utcNow && (DateA != null || DateB > utcNow)) continue;.
When DateA = null and DateB > utcNow it should fall into the continue but it doesn't.
Edit:
My mistake was assuming the opposite of DateA <= utcNow is DateA > utcNow. But it's DateA == null || DateA > utcNow
logic logical-operators boolean-logic
logic logical-operators boolean-logic
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
edited Nov 14 '18 at 14:17
Felipe
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
asked Nov 14 '18 at 3:18
FelipeFelipe
1687
1687
Are you looking forelse? As inif (thiscondition) dothis else dothat?
– Ken White
Nov 14 '18 at 3:50
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16
add a comment |
Are you looking forelse? As inif (thiscondition) dothis else dothat?
– Ken White
Nov 14 '18 at 3:50
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16
Are you looking for
else? As in if (thiscondition) dothis else dothat?– Ken White
Nov 14 '18 at 3:50
Are you looking for
else? As in if (thiscondition) dothis else dothat?– Ken White
Nov 14 '18 at 3:50
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16
add a comment |
3 Answers
3
active
oldest
votes
- Option 1 - use an
ELSEstatement
if(DateA <= utcNow || (DateA == null && DateB <= utcNow))
doSomething()
else{
dpSomethingElse();
- Option 2 - use
!in the operator
if(!(DateA <= utcNow || (DateA == null && DateB <= utcNow))) doSomethingElse();
- Option 3 - negation - The condition of DataA not being null will need to go first. There is some context missing but assuming you want to negate the expression by ensuring that give preference to DateA if it is greater than utcNow, else check for DateB being greater then utcNow
if((DateA != null && DateA > utcNow) || DateB > utcNow) doSomethingElse()
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
add a comment |
The opposite of DateA <= utcNow || (DateA == null && DateB <= utcNow) is
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
add a comment |
Your logic was pretty much alright @Felipe. Just that you overlooked a tiny aspect.
The negation of <= is not just > but it also includes a NULL value.just add these 2 conditionals along with an OR operator. This should work.
Check the updated statement below:
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 15 '18 at 7:04
RaiRai
844620
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
- Option 1 - use an
ELSEstatement
if(DateA <= utcNow || (DateA == null && DateB <= utcNow))
doSomething()
else{
dpSomethingElse();
- Option 2 - use
!in the operator
if(!(DateA <= utcNow || (DateA == null && DateB <= utcNow))) doSomethingElse();
- Option 3 - negation - The condition of DataA not being null will need to go first. There is some context missing but assuming you want to negate the expression by ensuring that give preference to DateA if it is greater than utcNow, else check for DateB being greater then utcNow
if((DateA != null && DateA > utcNow) || DateB > utcNow) doSomethingElse()
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
add a comment |
- Option 1 - use an
ELSEstatement
if(DateA <= utcNow || (DateA == null && DateB <= utcNow))
doSomething()
else{
dpSomethingElse();
- Option 2 - use
!in the operator
if(!(DateA <= utcNow || (DateA == null && DateB <= utcNow))) doSomethingElse();
- Option 3 - negation - The condition of DataA not being null will need to go first. There is some context missing but assuming you want to negate the expression by ensuring that give preference to DateA if it is greater than utcNow, else check for DateB being greater then utcNow
if((DateA != null && DateA > utcNow) || DateB > utcNow) doSomethingElse()
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
add a comment |
- Option 1 - use an
ELSEstatement
if(DateA <= utcNow || (DateA == null && DateB <= utcNow))
doSomething()
else{
dpSomethingElse();
- Option 2 - use
!in the operator
if(!(DateA <= utcNow || (DateA == null && DateB <= utcNow))) doSomethingElse();
- Option 3 - negation - The condition of DataA not being null will need to go first. There is some context missing but assuming you want to negate the expression by ensuring that give preference to DateA if it is greater than utcNow, else check for DateB being greater then utcNow
if((DateA != null && DateA > utcNow) || DateB > utcNow) doSomethingElse()
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
- Option 1 - use an
ELSEstatement
if(DateA <= utcNow || (DateA == null && DateB <= utcNow))
doSomething()
else{
dpSomethingElse();
- Option 2 - use
!in the operator
if(!(DateA <= utcNow || (DateA == null && DateB <= utcNow))) doSomethingElse();
- Option 3 - negation - The condition of DataA not being null will need to go first. There is some context missing but assuming you want to negate the expression by ensuring that give preference to DateA if it is greater than utcNow, else check for DateB being greater then utcNow
if((DateA != null && DateA > utcNow) || DateB > utcNow) doSomethingElse()
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
answered Nov 14 '18 at 4:01
curiouslevercuriouslever
807
807
add a comment |
add a comment |
The opposite of DateA <= utcNow || (DateA == null && DateB <= utcNow) is
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
add a comment |
The opposite of DateA <= utcNow || (DateA == null && DateB <= utcNow) is
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
add a comment |
The opposite of DateA <= utcNow || (DateA == null && DateB <= utcNow) is
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
The opposite of DateA <= utcNow || (DateA == null && DateB <= utcNow) is
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
answered Nov 14 '18 at 14:21
FelipeFelipe
1687
1687
add a comment |
add a comment |
Your logic was pretty much alright @Felipe. Just that you overlooked a tiny aspect.
The negation of <= is not just > but it also includes a NULL value.just add these 2 conditionals along with an OR operator. This should work.
Check the updated statement below:
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 15 '18 at 7:04
RaiRai
844620
add a comment |
Your logic was pretty much alright @Felipe. Just that you overlooked a tiny aspect.
The negation of <= is not just > but it also includes a NULL value.just add these 2 conditionals along with an OR operator. This should work.
Check the updated statement below:
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 15 '18 at 7:04
RaiRai
844620
add a comment |
Your logic was pretty much alright @Felipe. Just that you overlooked a tiny aspect.
The negation of <= is not just > but it also includes a NULL value.just add these 2 conditionals along with an OR operator. This should work.
Check the updated statement below:
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 15 '18 at 7:04
RaiRai
844620
Your logic was pretty much alright @Felipe. Just that you overlooked a tiny aspect.
The negation of <= is not just > but it also includes a NULL value.just add these 2 conditionals along with an OR operator. This should work.
Check the updated statement below:
(DateA == null || DateA > utcNow) && (DateA != null || DateB == null || DateB > utcNow)
answered Nov 15 '18 at 7:04
RaiRai
844620
answered Nov 15 '18 at 7:04
RaiRai
844620
answered Nov 15 '18 at 7:04
RaiRai
844620
answered Nov 15 '18 at 7:04
RaiRai
844620
844620
add a comment |
add a comment |
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Are you looking for
else? As inif (thiscondition) dothis else dothat?– Ken White
Nov 14 '18 at 3:50
Look up demorgans law
– Mitchel Paulin
Nov 14 '18 at 4:12
@MitchelPaulin Thanks! I knew that law, but when I looked at the Venn Diagrams I realized my mistake. See edit in question
– Felipe
Nov 14 '18 at 14:16