In my previous two posts about hashtables I provided examples for creating a hashtable, returning a specific value and a description around performance. This post will focus on the errors you should expect if you start using a hashtable.<\/p>\n
The most common exception I see happens when the data I’m storing in the hashtable is not unique. For example, in the first post in the series we created a simple hashtable from a list of HTML colors. If my input list had the color ‘red’ listed on two different lines, I would have seen an error similar to this:<\/p>\n
Add : Exception calling “Add” with “2” argument(s): “Item has already been added. Key in dictionary: ‘Red’ Key being This is an easy error message to generate if you want to see the actual error. Follow the examples in the first post and then try and re-add the color red using the following line:<\/p>\n The hashtable object includes a .Contains method, which can be used in an if statement to prevent this exception from happening:<\/p>\n This statement checks for the presence of a ‘Red’ item and only attempts to add if a value does not already exist.<\/p>\n","protected":false},"excerpt":{"rendered":" In my previous two posts about hashtables I provided examples for creating a hashtable, returning a specific value and a description around performance. This post will focus on the errors you should expect if you start using a hashtable. The … Continue reading
\n added: ‘Red'”
\nAt line:1 char:17
\n+ $colorCodeHT.Add <<<< ('Red','123456')\n + CategoryInfo : NotSpecified: (:) [], MethodInvocationException\n + FullyQualifiedErrorId : DotNetMethodException\n<\/font><\/p>\n\r\n$colorCodeHT.Add('Red','123456')\r\n<\/code><\/pre>\nif ($colorCodeHT.Contains('Red')) { \"Color 'red' has already been added\" } else { $colorCodeHT.Add('Red','123456') }<\/code><\/pre>\n