Question

I have the following script to delete a the digits at the end of an string and memorize the

initValues: (input)->
    value = $(input).val()

    split =  input.selectionStart

    @sub1 = value.substring(0, split).replace /\d*$/, (match) =>
        @firstDigit = match
        ''

    @firstDigit 

Wonder if there is a way to keep firstDigit in the scope of the initValue function like this:

initValues: (input)->
    value = $(input).val()

    split =  input.selectionStart

    @sub1 = value.substring(0, split).replace /\d*$/, (match) ->
        firstDigit = match
        ''

    firstDigit 

Answer 1

Declare it outside the callback function:

initValues: (input)->
    value      = $(input).val()
    split      = input.selectionStart
    firstDigit = null
    @sub1 = value.substring(0, split).replace /\d*$/, (match) ->
        firstDigit = match
        ''
    firstDigit

Demo: http://jsfiddle.net/ambiguous/uRFNq/

You might want to use a different name than firstDigit though as firstDigit won’t necessarily contain the first digits in the string, it will contain the trailing digits.