The docs say The String in the switch expression is compared with the expressions associated with each case label as if the String.equals method were being used. Since it says as if my guess would be it does not though the internal implementation would be the same as .equals() method.
The Include annotation is used on the member(s) you want to include in the equals and hashCode methods. If you want to specify exactly which members should be used (instead of the default of all non-static non-transient members), you could use the onlyExplicitlyIncluded = true option in the @EqualsAndHashCode annotation: @EqualsAndHashCode(onlyExplicitlyIncluded = true) @Table(name = … Read more
The difference is the Objects.equals() considers two nulls to be “equal”. The pseudo code is: if both parameters are null or the same object, return true if the first parameter is null return false return the result of passing the second parameter to the equals() method of the first parameter This means it is “null … Read more
The string comparison with StringComparison.OrdinalIgnoreCase works in memory or with IEnumerable<T>. You are trying to use it with IQueryable<T>, but the provider of your queryable does not understand it. This works for me: db.Users.FirstOrDefault( s => s.Username.Equals(username, StringComparison.OrdinalIgnoreCase) );
There’s no simple answer for this question. Anyone who says always use one or the other is giving you poor advice, in my opinion. There are actually several different methods you can call to compare object instances. Given two object instances a and b, you could write: Object.Equals(a,b) Object.ReferenceEquals(a,b) a.Equals(b) a == b These could … Read more
Domain-Driven Design makes the distinction between Entities and Value Objects. This is a good distinction to observe since it guides how you implement Equals. Entities are equal if their IDs equal each other. Value Objects are equal if all their (important) constituent elements are equal to each other. In any case, the implementation of GetHashCode … Read more
It’s the concatenating assignment operator. It works similarly to: $var = $var . “value”; $x .= differs from $x = $x . in that the former is in-place, but the latter re-assigns $x.
From documentation, {{if pipeline}} T1 {{end}}: If the value of the pipeline is empty, no output is generated; otherwise, T1 is executed. The empty values are false, 0, any nil pointer or interface value, and any array, slice, map, or string of length zero. Dot is unaffected. So if you want to check if the … Read more
Implementing IEquatable<T> for a Value Type Implementing IEquatable<T> for a value type is a little bit different than for a reference type. Let’s assume we have the Implement-Your-Own-Value-Type archetype, a Complex number struct. public struct Complex { public double RealPart { get; set; } public double ImaginaryPart { get; set; } } Our first step … Read more
No, you can’t. What you can do, however, is use an abstract base class instead of an interface, and make equals() abstract: abstract class Command { // put other methods from Command interface here public abstract boolean equals(Object other); public abstract int hashCode(); } Subclasses of Command must then provide their own equals and hashCode … Read more