Integer indexing array: Shift left

Write a statement that shifts row array attendanceValues one position to the left. The rightmost element in shiftedValues also

keeps its value.

Ex: $10,20,3040$ after shifting becomes $20,30,40,40.$

Function $(?$

function attendanceValues $=$ ShiftValues$($attendanceValues$)$

$\%$ attendanceValues: Array contains $4$ elements recording attendence for the last $4$ shows

$\%$ Change indexing values

attendanceValues $(1$:$1)=$ attendanceValues $(1$:$|1)$;

end

Code to call your function?