Specifically for php, traditionally in other editors (such as np++) when you double click on a variable name, for example, it would select just the name without the '$'. In VSCode it selects the variable name plus the '$' and often also a tailing '-' if there is one.
Take
$foo->bar();
Current Behavior:
double clicking 'foo' selects:
$foo-
Desired Behavior:
double clicking 'foo' selects:
foo
Edit: Here's the github issue: https://github.com/Microsoft/vscode/issues/2036
Since this issue has been resolved it's worth adding this answer.
You can now accomplish this in your settings by modifiying the "editor.wordSeparators"
setting.
Here is the default:
"editor.wordSeparators": "`~!@#$%^&*()-=+[{]}\\|;:'\",.<>/?"
To allow the selection of $foo
you can remove the $
from the above string.