> You could even use filter(function(f){f.name==‘abc’;}).length > 0not really, that's a long way to find what you are looking for, `some` stops ASAP instead. > The focus of this proposal is that the purpose of .valueOf and .toString I think those have valid use cases and changing a method already shipped long time ago to make use of those methods is surely not one of them. This will never happen, you might have better luck proposing a new method (yet I have the feeling it won't happen neither because it's too easy to do on user land). Regards On Wed, Jun 20, 2018 at 8:54 PM, Mike Simon <[email protected]> wrote: > True, there are many other ways to make this work. You could even use > filter(function(f){f.name==‘abc’;}).length > 0 . > > The focus of this proposal is that the purpose of .valueOf and .toString > are to allow for objects to return a default value without requiring the > matching method to know about the contents or property names of any of > next. > > Array.prototype.some, and any method mentioned above require a that a > content aware function be passed in to facilitate the match. This proposal > mitigates that, and allows Array.prototype.includes to evaluate the object > as the object design was intended. > > On Jun 20, 2018, at 11:33 AM, Andrea <[email protected]> > wrote: > > It looks like you want included to use `==` for comparison, opening a > whole new world of issues. > > You have `some` and your code to do that with ease, same goes for `find` > or `findIndex`, very appropriate for this use case. > > ```js > items.some(o => o == 'abc'); > ``` > > Regards > > On Wed, Jun 20, 2018 at 8:27 PM, Mike Simon <[email protected]> wrote: > >> [Proposal] Array.prototype.includes should evaluate object.toString >> and/or object.valueOf when determining a match >> >> The problem: >> >> If I have a list of objects that contain a toString() prototype that >> returns a value from the object, Array.prototype.includes does not return >> true if the value/string returned from the object is a match for the >> parameter value. >> >> Test code: >> >> var thingy = function(name) {this.name=name;}; >> thingy.prototype.valueOf = function(){return this.name}; >> thingy.prototype.toString = function(){return this.name}; >> var items = [new thingy('abc'),new thingy('def')]; >> var inc = items.includes('abc'); >> alert(items[0]); // alerts abc >> alert(inc); // returns false >> >> While it’s possible to create this as a list of strings using map, this >> would seem to conserve memory, as well as reduce the complexity of the code >> to perform this operation. >> >> Link: https://developer.mozilla.org/en-US/docs/Web/JavaScrip >> t/Reference/Global_Objects/Array/includes >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >
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