Difference between revisions of "CSC111 Exercises with Global Variables"
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| − | + | ||
| + | def f1( x ): | ||
| + | global A | ||
| + | A = [] | ||
| + | print( "f1", x, A ) | ||
| + | A.append( 10 ) | ||
| + | A.append( 20 ) | ||
| + | print( "f1", x, A ) | ||
| + | |||
| + | A = [1, 2, 3] | ||
| + | print( "A = ", A ) | ||
| + | f1( 30 ) | ||
| + | print( "A = ", A ) | ||
| + | |||
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>>> | >>> | ||
| − | + | A = [1, 2, 3] | |
| + | f1 30 [] | ||
| + | f1 30 [10, 20] | ||
| + | A = [10, 20] | ||
>>> | >>> | ||
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Revision as of 18:28, 24 April 2014
--D. Thiebaut (talk) 15:57, 24 April 2014 (EDT)
Explain the behavior of the different code sections shown below along with their output.
Case 1
|
A = 3
def f1( x ):
print( "f1", x, A )
print( "A = ", A )
f1( 30 )
|
>>>
A = 3
f1 30 3
>>>
|
Case 2
|
def f1( x ):
print( "f1", x, A )
A = 3
print( "A = ", A )
f1( 30 )
|
>>>
A = 3
f1 30 3
>>>
|
Case 3
|
A = 3
def f1( x ):
print( "f1", x, A )
A = 5
print( "A = ", A )
f1( 30 )
print( "A = ", A )
|
>>> A = 3 Traceback (most recent call last): File "/Users/thiebaut/Desktop/PYTHON/globalExercises.py", line 8, in <module> f1( 30 ) File "/Users/thiebaut/Desktop/PYTHON/globalExercises.py", line 4, in f1 print( "f1", x, A ) UnboundLocalError: local variable 'A' referenced before assignment >>> |
Case 4
|
A = 3
def f1( x ):
global A
print( "f1", x, A )
A = 5
print( "A = ", A )
f1( 30 )
print( "A = ", A )
|
>>>
A = 3
f1 30 3
A = 5
>>>
|
Case 5
|
def f1( x ):
A = []
print( "f1", x, A )
A.append( 10 )
A.append( 20 )
print( "f1", x, A )
A = [1, 2, 3]
print( "A = ", A )
f1( 30 )
print( "A = ", A )
|
>>>
A = [1, 2, 3]
f1 30 []
f1 30 [10, 20]
A = [1, 2, 3]
>>>
|
Case 6
|
def f1( x ):
global A
A = []
print( "f1", x, A )
A.append( 10 )
A.append( 20 )
print( "f1", x, A )
A = [1, 2, 3]
print( "A = ", A )
f1( 30 )
print( "A = ", A )
|
>>>
A = [1, 2, 3]
f1 30 []
f1 30 [10, 20]
A = [10, 20]
>>>
|
Case
|
|
>>>
>>>
|
