跳到主要内容

Variable Scope and References

1. What is the value of a after the following is evaluated?

def f(x, y):
y = y + [x]
return y

a = [1,3]
a = f(2,a) + a

(a) [1, 3, 1, 2]

(b) [1, 3, 2, 1, 3]

(c) [2, 1, 3, 3, 1, 2]

(d) [1, 2, 3, 1, 2, 3]

(e) None of the above

2. What is the value of a after the following is evaluated?

def f(x, y):
y = y + [x]
return y

a = [2,1]
a = f(1,a) + 2 * a

(a) [1, 3, 1, 2]

(b) [2, 1, 1, 2, 1, 2, 1]

(c) [2, 1, 1, 4, 2]

(d) [1, 2, 3, 1, 2, 3, 2]

(e) None of the above

3. What is the value of a after the following code is executed?

def f(x):
a = 70
x += a
return a

a = 50
f(a)

(a) 50

(b) 70

(c) 120

(d) None of the above

4. What is the value of x after the following code is executed?

def f(l, a, b):
l.append(a)
l = l + [b]
return l

x = [5, 9]
x = f(x, 2, 1) + x

(a) [5, 9, 2, 1]

(b) [5, 9, 2, 1, 5, 9]

(c) [5, 9, 2, 1, 5, 9, 2]

(d) [5, 9, 2, 1, 5, 9, 2, 1]

(e) Error

5. What is the value of y after the following code is executed?

def g(x):
a = 11
x += [2]
return a

a = 10
b = [3, 4]
g(b)
y = b + [a]

(a) [3, 4, 2, 10]

(b) [3, 4, 2, 11]

(c) [3, 4, 10]

(d) [3, 4, 11]

(e) None of the above

6. What is the value of x after the following code is executed?

def f(v, u, b):
v.pop(u)
v = v + [b]
return v

x = [2, 3, 5]
x = f(x, 2, 3) + x

(a) [2, 3, 3, 2, 3, 5]

(b) [2, 3, 5, 2, 3]

(c) [2, 3, 5, 3, 2]

(d) [2, 3, 3, 2, 3]

7. What is the value of the global variable a after the following code is executed?

def f(x):
a = 100
x += a
return x + a

a = 1
f(a)

(a) 1

(b) 100

(c) 101

(d) 201

(e) Error

8. What is the value of x after the following code is executed?

def f(l, a, b):
l.append(a)
l = l + [b]
return l

x = [5, 9]
x = f(x, 2, 1) + x

(a) [5, 9, 2, 1]

(b) [5, 9, 2, 1, 5, 9]

(c) [5, 9, 2, 1, 5, 9, 2]

(d) [5, 9, 2, 1, 5, 9, 2, 1]

(e) Error

9. What is the value of the global variable a after the following code is executed?

def f(x):
a = 3
x = x / a
return (a + x) % x

a = 9
f(a)

(a) 9

(b) 3

(c) 0

(d) 0.0

(e) Error

10. What is the value of x after the following code is executed?

def f1(a, b):
return a / b

def f2(a, b):
b = 10
return f1(b, a)

x = f2(8, 4)

(a) 0.5

(b) 1.25

(c) 2.0

(d) 2.5