Comparing floating point values using the == operator is very error prone; two values that should be equal may not be due to arithmetic rounding errors. The common way to compare these is to use an epsilon: bool double_equals(double a, double b, double epsilon = 0.001) { return std::abs(a – b) < epsilon; }
public static class JaroWinklerDistance { /* The Winkler modification will not be applied unless the * percent match was at or above the mWeightThreshold percent * without the modification. * Winkler’s paper used a default value of 0.7 */ private static readonly double mWeightThreshold = 0.7; /* Size of the prefix to be concidered by … Read more
It’s a mechanism to avoid mistakes like this: if ( var = NULL ) { // … } If you write it with the variable name on the right hand side the compiler will be able catch certain mistakes: if ( NULL = var ) { // not legal, won’t compile // … } Of … Read more
The linked comparisons are very thorough, but as far as the main differences I would note the following: C# has anonymous methodsVB has these now, too C# has the yield keyword (iterator blocks)VB11 added this VB supports implicit late binding (C# has explicit late binding now via the dynamic keyword) VB supports XML literals VB … Read more
here is a slightly modified version from colin’s. class Hash def diff(other) (self.keys + other.keys).uniq.inject({}) do |memo, key| unless self[key] == other[key] if self[key].kind_of?(Hash) && other[key].kind_of?(Hash) memo[key] = self[key].diff(other[key]) else memo[key] = [self[key], other[key]] end end memo end end end It recurses into the hashes for more efficient left and right {a: {c: 1, b: … Read more
For Swift 5 see rustylepord’s answer. Update for Swift 3: let letters = CharacterSet.letters let digits = CharacterSet.decimalDigits var letterCount = 0 var digitCount = 0 for uni in phrase.unicodeScalars { if letters.contains(uni) { letterCount += 1 } else if digits.contains(uni) { digitCount += 1 } } (Previous answer for older Swift versions) A possible … Read more
I think you meant something like “*” (star) as a wildcard for example: “a*b” => everything that starts with “a” and ends with “b” “a*” => everything that starts with “a” “*b” => everything that ends with “b” “*a*” => everything that has an “a” in it “*a*b*”=> everything that has an “a” in it, … Read more
You’re right to be slightly nervous about ==: struct NeverEqual: Equatable { } func ==(lhs: NeverEqual, rhs: NeverEqual)->Bool { return false } let x = [NeverEqual()] var y = x x == y // this returns true [NeverEqual()] == [NeverEqual()] // false x == [NeverEqual()] // false let z = [NeverEqual()] x == z // … Read more
Is it better to use obj.nil? or obj == nil It is exactly the same. It has the exact same observable effects from the outside ( pfff ) * and what are the benefits of both. If you like micro optimizations all the objects will return false to the .nil? message except for the object … Read more