How to create an associative array, preferably a one-liner? - powershell

Question

I have this:
$str = "name = username`nemail = user#example.com"
Which is LF separated string, as part of an INI file. I want to create associative array so that for instance $vars['name'] will return 'username'. This is how I split it to lines:
$vars = ([regex]'\n').Split($str) | %{ $_.Trim() }
What change should I make to the line above?

Answer 1

If you are a lucky owner of Powershell 4 then you can use ConvertFrom-StringData cmdlet:
$str = "name = username`nemail = user#example.com"
$vars = ConvertFrom-StringData $str
Result:
PS C:\> $vars
Name Value
---- -----
name username
email user#example.com

Answer 2

A more PoSh version of PeterK's answer would look like this:
$vars = #{}
$str.Trim() -split "\s*`n\s*" | % {
$key, $value = $_ -split '\s*=\s*'
$vars[$key] = $value
}
Using $vars[$key] = $value instead of $vars.Add($key, $value) avoids errors in case you have duplicate keys.
You could also split the string into an array of alternating key and value fields and then fill the hashtable from that array:
$vars = #{}
$list = $str.Trim() -split "\s*`n\s*" -split '\s*=\s*'
while ($list) {
$key, $value, $list = $list
$vars[$key] = $value
}
Each of the examples can be mangled into a single line by separating the statements with semicolons:
$vars = #{}; $str.Trim() -split "\s*`n\s*" | % { $key, $value = $_ -split '\s*=\s*'; $vars[$key] = $value }
$vars = #{}; $list = $str.Trim() -split "\s*`n\s*" -split '\s*=\s*'; while ($list) { $key, $value, $list = $list; $vars[$key] = $value }

Answer 3

It's not a one-liner, but one way to do it is:
$hashtable = #{};
$key_value_pairs = $str.Split("`n");
foreach($key_value in $key_value_pairs)
{
$key_value_pair = $key_value.Split('=');
$hashtable.Add($key_value_pair[0].Trim(), $key_value_pair[1].Trim());
}
The input string is first split into an array, each item containing a key-value pair in a single line. For each key-value pair, we split them into a 'key' and 'value' on "=", again into a regular array. Both the key and value are trimmed and added to the hash table. Once this is done, $hashtable["name"] will return "username" and $hashtable["email"] will return "user#example.com"