boolean-expression

问题 I have to convert a number to comma format. E.g 12345 => 12,345. I have my solution : function convert(n) { n = n.toString(); var result = ''; var count = 0, var idx = n.length - 1; while (r = n[idx]) { count++; result = ((count % 3 == 0 && count != n.length) ? ',' : '') + r + result; idx--; } return result; } But someone else used : result = ((count % 3 != 0 || count == n.length) ? '' : ',') + r + result; They both work but now I am confused about my own solution and just lost why they both

问题 This question already has answers here : 'AND' vs '&&' as operator (10 answers) Closed 4 years ago . Why is $x true in this statment? $x = true and false; I've got the problem with some variables but I could reduce the problem to the primitive boolean values. Update: As you see in the replies the effect has to do with the operator precedense in PHP. There is also a good explanation about the problem in this question, which I couldn't find in the net before since I didn't know that I have a

问题 please help me with simplifying this one. I am a bit new to these.. (A'BC') + (A'B'C) + (A'BC) + (AB'C) the book i use shows and answer, which is, Answer = A'B + B'C I tried simplifying, but I get stucked with two eXors, my simplification so far goes like this... (A'BC') + (A'B'C) + (A'BC) + (AB'C) A (BC' + B'C) + C (A'B + AB') This doesn't seem to be a write way, Please someone help me simplify this, and please show step by step, as I am sort of new.. Also I don't get how to simplify eXor

问题 I am trying to solve a combinatorial problem by using a SAT Solver. This involves the following steps: Encode the problem as set of boolean expressions. Translate a conjunction of the expressions into CNF/DIMACS (using home grown tools, bc2cnf, bool2cnf or Limboole) Solve the CNF (using SAT Solvers like Cryptominisat, Plingeling, Clasp or Z3) Translate the solution (assuming a "SAT" result) back into the problem domain This works in my case for small samples. But for more challenging ones,

问题 I have a big boolean formula to solve, due to the reason of the redaction, I have to paste an image here: Also, I have already a function area to measure the dimension of 4 integers: area(c,d,e,f)=|c−d|×|e−f| I would like to do more than just figuring out if the formula is satisfiable: I am looking for an optimal 6-tuple (a,b,c,d,e,f) which makes the big formula TRUE and area(c,d,e,f) is greater or equal to the dimension of any other 6-tuple which also satisfies the formula. In other word,

问题 I tried to ask this before, and messed up the question, so I'll try again. Is it possible to make an object return false by default when put in an if statement? What I want: $dog = new DogObject(); if($dog) { return "This is bad;" } else { return "Excellent! $dog was false!" } Is there a way this is possible? It's not completely necessary, but would save me some lines of code. thanks! 回答1: No, PHP has no support for operator overloading. Maybe they'll add it in a future version. 回答2: Use the

问题 I have a JPQL statement to return a schedule of sports games: SELECT NEW com.kawoolutions.bbstats.view.ScheduleGameLine( ga.id AS gid , ga.scheduledTipoff AS scheduledtipoff ... , sch.finalScore AS homefinalscore , sca.finalScore AS awayfinalscore , sch.finalScore IS NOT NULL AND sca.finalScore IS NOT NULL AS hasfinalscore ) I want the last expression (boolean) to evaluate to a boolean to indicate whether a game's final score has been completely reported or not (two entities of type Score,

问题 I ran across an interesting bug the other day. I was testing an array to see if it evaluated to Boolean false, however just directly evaluating it always returned true: > !![] true Okay, so basically any array I put in there will be true regardless, right? I run this in the JavaScript console just for fun: > [] == true false What is going on here? 回答1: It has to do with the The Abstract Equality Comparison Algorithm versus the algorithm used to tranform a value to a boolean. By looking at the

问题 Anybody knows of an algorithm to simplify boolean expressions? I remember the boolean algebra and Karnaught maps, but this is meant for digital hardware where EVERITHING is boolean. I would like something that takes into account that some sub-expressions are not boolean. For example: a == 1 && a == 3 this could be translated to a pure boolean expression: a1 && a3 but this is expression is irreducible, while with a little bit of knowledge of arithmetics everibody can determine that the

问题 I didn't know this was possible (is it?) The below code apparently logs values 1 to 5, then breaks out of the 'for' loop, because the 'false' value is returned. function x() { for (var i = 0; i < 10; i++) { console.log(i); if (i == 5) return false; } return true } console.log(x()); My question is: How come the for loop short-circuits when 'false' is returned? I looked at MDN but there is nothing there about using 'false' to break out of the for loop. Also tried looking at ECMA specs, but