1,930 questions
0
votes
2
answers
9k
views
Comparing boolean values
I am facing an issue while comparing boolean values, I want the loop to enter inside the block but its not entering the block.
else if (!(keyCompare.contains(compareKey)) || (save == true)) {
//do ...
CommunityBot
- 1
73
votes
4
answers
43k
views
Why are negative numbers not always true or false?
-1 == true; // false
-1 == false // false
-1 ? true : false; // true
Can anyone explain the above output? I know I could work round this by comparing to 0 but I'm interested. I'd expect ...
- 14.5k
0
votes
0
answers
35
views
Calling a boolean vs. not equal to -1 [duplicate]
I am working on a function that takes the domain name from the respective prefixes such as www, .com, etc. and am a little confused on what the difference between calling my alias to be true and ...
- 21.3k
106
votes
9
answers
10k
views
Naming of TypeScript union and intersection types
I can't understand the logic behind the terms intersection types and union types in TypeScript. I'm thinking of interfaces (or classes) as sets of properties.
The logical conjunction operator & is ...
- 2,563
1
vote
1
answer
124
views
How to set a boolean flag True after entry and back to False after exit using Pandas (vectorized)?
I'm working with a Pandas DataFrame where I need to track a boolean flag (in_position)
that becomes True after an entry_signal and resets to False only after an exit_signal.
This must be done ...
- 267k
4
votes
2
answers
500
views
Check if all values of Polars DataFrame are True
How can I check if all values of a polars DataFrame, containing only boolean columns, are True?
Example df:
df = pl.DataFrame({"a": [True, True, None],
"b": [...
- 2,127
3
votes
2
answers
120
views
In Javascript, is A == !B always the same as A != B
Refactoring some old code, I found the following:
someVar == !otherVar
That doesn't look that legible, I thought that could be written as:
someVar != otherVar
It seems logic to do so. But, since this ...
0
votes
2
answers
184
views
Is there a good algorithm for the minimal computation of a CNF without extra variables?
I'm currently working on tranforming logical queries for database systems from a DNF form into a CNF form, focussed on queries which have a similar form to
(a and b and c and d and e1) or (a and b and ...
- 19.6k
2
votes
3
answers
2k
views
Boolean formula for a graph vertex-colouring algorithm
I have a graph which has 5 vertexes.
Graph g1 = new Graph(5);
g1.addEdge(0, 1);
g1.addEdge(0, 2);
g1.addEdge(1, 2);
g1.addEdge(1, 3);
g1.addEdge(3, 2);
...
- 67
0
votes
1
answer
45
views
Troubleshooting of Boolean combination of AND and OR conditions in Excel Formula [duplicate]
I am trying to set up an Excel conditional formula with both AND and OR criteria.
However, the last 2 criteria OR(Table1[Col5]=$J$4,Table1[Col5]=$K$4) and OR(Table1[Col6]=Pivot!$J$5,Table1[Col6]=Pivot!...
- 7,674
1
vote
2
answers
256
views
System of Boolean Equations
I am working on solving a system of boolean equations. Specifically, I am trying to find the values of bit vectors S1...S3 and/or C1...C3 such that their XOR results are given in the table below (in ...
- 11.5k
28
votes
3
answers
197k
views
How to combine multiple conditions in a PowerShell if-statement
How do you chain multiple sets conditions together when you want either one set or the other set of 2 conditions to be true?
To be more precise, I want to do:
If User is logged in AND Operating system ...
- 21.3k
0
votes
0
answers
58
views
Logical condition equivalent with restrictions
I am developing an Azure DevOps custom task. Part of the setting of the inputs is a VisibleRule which can contain a condition which will determine if the input will be visible, if the condition is ...
- 18.5k
1
vote
5
answers
2k
views
Python Function to look for words in any provided sentence
I am new to programming and I just started learning Python by doing online classes at work. I am currently on the topic of writing a function. I thought that it will be useful to have a function that ...
- 1
9
votes
0
answers
321
views
Limiting the depth of Boolean expressions
I am given a Boolean expression of arbitrary depth, like (A or (B and (C or (~D and E) or F) or (G and H))). There can be any number of terms at each level.
I want to limit the depth of the ...
- 583
1
vote
2
answers
285
views
Simplify a boolean expression with 4 variables to 3 variables
I'm doing some simplifications for a circuit and I ended up getting the following expression:
A.C'.D' + A.B'.C' + B.C.D' + B'.C.D + A'.B'.D'
which translates to the truth table where 0, 2, 3, 6, 8, 9, ...
CommunityBot
- 1
-2
votes
1
answer
162
views
c++: Is (a || b) || c; equivalent to if (!a && !b) { c; }
I'm updating somebody else's code.
They did the following :
bool a();
bool b();
a() || b() || std::clog << "whine about something" << std::endl;
I'm replacing the std::clog bit ...
0
votes
1
answer
58
views
How do I construct a boolean circuit from a boolean function when I cancelled our one of the variables?
I was given a truth table of four variables, let's call them A,B,C,D. I found every instance where the truth table was true and turned it into a function:
F = (-A^-B^-C^-D) v (-A^-B^-C^ D) v (-A^-B^ C^...
- 11.5k
615
votes
65
answers
208k
views
Check if at least two out of three booleans are true
An interviewer recently asked me this question: given three boolean variables, a, b, and c, return true if at least two out of the three are true.
My solution follows:
boolean atLeastTwo(boolean a, ...
- 37.1k
25
votes
3
answers
126k
views
What is the difference between Verilog ! and ~?
So it ended up that the bug that had kept me on for days, was a section of code that should have evaluated to False evaluating to True. My initial code went something like:
if(~x && ~y) begin
...
- 1
2
votes
4
answers
11k
views
boolean algebra - build a OR gate as an NAND gate
I am trying to wrap my mind around how to do this. For what I understand is that a set of logic gates is called "functionally complete" if some combination of the gates can be used to do ...
- 209
6
votes
5
answers
13k
views
Finding the maximum of two integers in binary using bit logic only
This is a bit tricky, it's a nice challenge for those up to the task I think. And I did search through all the questions previously asked, but I couldn't find what I want.
The aim here is, given 2 ...
38
votes
10
answers
25k
views
How can I implement user-friendly boolean logic in a web form GUI?
Currently I have a web application where a user can use dropdown lists to generate SQL SELECT statements like so:
Column Select Dropdown | Operator Dropdown (= != > < <= >=) | Value select ...
-2
votes
1
answer
145
views
Counter in custom sequence using JK flip-flops
I need a counter that displays a custom number sequence instead of counting up or down.
I know I'm gonna need 3 JKs, meaning 2 ICs with 2 flip-flops. a few logic gates, but I don't really get how I ...
5
votes
4
answers
386
views
How to evaluate nested boolean/logical expressions in Python?
I'm working on a complex rule parser that has the following properties:
A space character separates rules
A "+" character indicates an "AND" operator
A "," character ...
- 19.6k