When using the useState hook in React, the common usage pattern looks like
const [myVariable, setMyVariable] = useState();
This is very repetitive, and the camelcase means that the variable name needs to be capitalised for the set variable, which means it can't be easily copy pasted, or added with multiple cursors.
The "Insert useState line" command can be accessed from the command palette, but it's recommeded you set up a keybinding for it. Enter your variable name into the textbox (e.g. myVariable in the above example), and the properly camelcased line will be added. You may still need to import useState yourself.
Optionally, you can specify its default value and/or its type after the variable name. Those three parts should be separated by a space. For example:
// variable name only
myVariable
// variable name and default value
myVariable false
// variable name and default value and type
myVariable false boolean
// variable name and type, there should be two spaces
myVariable boolean
// union type is ok
myVariable 1 number | stringIf the variable type is string, a pair of quotes will be added around the default value.