idNumber

Check if an Israeli id number is legal.

An Israeli id number must contain 9 digits exactly, while the last one (the 9th digit) is used as a check digit.

The calculation is done as follows:

id number: x x x x x x x x y (y = check digit)

    ______________________
    x  x  x  x  x  x  x  x
    1  2  1  2  1  2  1  2
    ______________________
    (x*1)+(x*2)+(x*1)+(x*2) ...... = sum
    sum + y = N
    if N/10 equals an integer (a whole number) - the id number is legal