equality

I think that my code should make the ViewBag.test property equal to "No Match" , but instead it throws an InvalidOperationException . Why is this? string str = "Hello1,Hello,Hello2"; string another = "Hello5"; string retVal = str.Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries) .First(p => p.Equals(another)); if (str == another) { ViewBag.test = "Match"; } else { ViewBag.test = "No Match"; //this does not happen when it should } As you can see here , the First method throws an InvalidOperationException when the sequence on which it is called is empty. Since no element of the

After reading a related question about using slices in maps, I became curious about equality in Go. I know it's possible to override the equals method of a Java Object . Is there a similar way to define how Go checks user defined types/structs for equality? If so, there would be a workaround for the issue referenced above. I thought using interface{} values might offer a solution but I received the error message panic: runtime error: hash of unhashable type []int . Go supports equality checking structs. type Person struct { Name string } a := Person{"Bill DeRose"} b := Person{"Bill DeRose"} a

Is there a uniform method to perform equality with type checking? Unfortunately val objectA:String = "test" val objectB:Int = 2 objectA == objectB the equality operator == doesn't complain if objectB is a Int while objectA is a String. I would need an operator like === that perform type checking as well (and I hope it is uniform to all scala obj). Does such operator exist? You need to look at scalaz 's === for type-safe equals - it's implemented as type class there. You can also watch talk by Heiko Seeberger , where he describes how it's implemented: http://days2011.scala-lang.org/node/138/275

In TypeScript, I want to compare two variables containing enum values. Here's my minimal code example: enum E { A, B } let e1: E = E.A let e2: E = E.B if (e1 === e2) { console.log("equal") } When compiling with tsc (v 2.0.3) I get the following error: TS2365: Operator '===' cannot be applied to types 'E.A' and 'E.B'. Same with == , !== and != . I tried adding the const keyword but that seems to have no effect. The TypeScript spec says the following: 4.19.3 The <, >, <=, >=, ==, !=, ===, and !== operators These operators require one or both of the operand types to be assignable to the other.

I am searching a []interface{} slice for a given interface{} value: var v interface{} for i := 0; i < len(A); i++ { if (A[i] == v) { fmt.Println("Gotcha!") break } } In the trivial case the types are int . However what should I do if, for example, the types are some custom struct ? Brian Vanover Thanks to @CodingPickle comment, I provide the following from the Go Programming Language Specification The equality operators == and != apply to operands that are comparable. Regarding interface{} s and structs : Interface values are comparable. Two interface values are equal if they have identical