_.mixin
  array_shift: (inputArr) ->
    props             = false
    shift             = undefined
    pr                = ''
    allDigits         = /^\d$/
    int_ct            = -1
    _checkToUpIndices = (arr, ct, key) ->
      #Deal with situation, e.g., if encounter index 4 and try to set it to 0, but 0 exists later in loop (need to
      #increment all subsequent (skipping current key, since we need its value below) until find unused)
      if arr[ct] isnt undefined
        tmp= ct
        ct += 1
        if ct is key then ct += 1
        ct= _checkToUpIndices(arr, ct, key)
        arr[ct]= arr[tmp]
        delete arr[tmp]
      return ct
    if inputArr.length is 0 then null
    if inputArr.length > 0 then _.array_shift(inputArr)