Hashset in TypeScript

I am attempting to do something very basic in TypeScript. Get a list of unique strings while parsing a map as referenced in this post. Here is what I am attempting to do: ``` let myData = new Array<string>(); for (let myObj of this.getAllData()) { let name = myObj.name; console.log("## we have " + name); console.log("### is property ? " + myData.hasOwnProperty(name)); if (!myData.hasOwnProperty(name)){ myData.push(name); } } ``` My printout will always evaluate to false for any string, duplicate or not. Here is some sample output: ``` ## we have COW ### is property ? false ## we have COW ### is property ? false ## we have RAODN ### is property ? false ## we have COOL ### is property ? false ``` However, when the process completes, my list contain duplicates. I have tried looking at this documentation, but there is no mention of a 'hashset' or any set in general. Is there something equivalent in TypeScript of a Set? i.e A list of unique elements