Question

Observe the following program carefully, and identify the error:

mynum = 9
def add9():
       mynum = mynum + 9
       print mynum
add9()                          #function call

Answer 1

There are two errors in the given program.

1. In line 1, ‘mynum’ variable is defined which is a global variable. However, in line 3, a variable with the same name is defined again. Therefore, 'mynum' is treated as a new local variable. As no value has been assigned to it before the operation, hence, it will give an error. The local variable can either be changed to a different name or a value should be assigned to the local 'mynum' variable before line 3.
2. The syntax of the ‘print’ function is incorrect. The correct syntax will be ‘print(mynum)’.