Hackerrank Control Flow and Looping 5

Question 1

What is the output of:
```python
result = [i for i in range(10) if i % 3 == 0]
print(result)
```

Accepted Answer

[0, 3, 6, 9]

Answer

range(10) produces 0-9; filtering by i%3==0 keeps 0, 3, 6, 9.

Question 2

What is the output of:
```python
i = 0
while i < 3:
    i += 1
print(i)
```

Accepted Answer

3

Answer

The loop runs while i < 3, incrementing i each time; after the loop i equals 3.

Question 3

Which of the following correctly uses `all()` to check that every number in a list is positive?

Accepted Answer

all(x > 0 for x in nums)

Answer

all() with a generator expression returns True only if every element satisfies the condition.

Question 4

What is the output of:
```python
for char in 'abc':
    if char == 'b':
        continue
    print(char)
```

Accepted Answer

a c

Answer

continue skips 'b', so only 'a' and 'c' are printed.

Question 5

What does this code print?
```python
found = False
for n in [4, 8, 15, 16]:
    if n > 10:
        found = True
        break
print(found, n)
```

Accepted Answer

True 15

Answer

The first n > 10 is 15, which sets found=True and breaks, leaving n as 15.

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