Increment and decrement operators in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to increment the variable count by 1.

C++

int count = 5;
count[1];

Drag options to blanks, or click blank then click option'

A++

B--

C+=

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using the decrement operator -- instead of increment.

Using += without specifying the amount.

The increment operator ++ increases the value of count by 1.

2fill in blank

medium

Complete the code to decrement the variable value by 1.

C++

int value = 10;
value[1];

Drag options to blanks, or click blank then click option'

A--

B++

C+=

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using the increment operator ++ instead of decrement.

Using -= without specifying the amount.

The decrement operator -- decreases the value of value by 1.

3fill in blank

hard

Fix the error in the code to correctly increment num.

C++

int num = 7;
num = num[1];

Drag options to blanks, or click blank then click option'

A++

B- 1

C--

D+ 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using ++ after assignment operator.

Using decrement operators instead of increment.

To increment num by 1 using assignment, you add 1 with + 1.

4fill in blank

hard

Fill both blanks to create a map of numbers to their squares using increment in the loop.

C++

std::map<int, int> squares;
for (int i = 1; i [1] 5; i[2]) {
    squares[i] = i * i;
}

Drag options to blanks, or click blank then click option'

A<=

B<

C++

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using i <= 5 causes the loop to run one extra time.

Using decrement operator -- in the loop.

The loop runs while i is less than 5, and i++ increments i by 1 each time.

5fill in blank

hard

Fill all three blanks to create a map of uppercase letters to their ASCII codes, incrementing the letter.

C++

std::map<char, int> ascii_map;
for (char ch = 'A'; ch [1] 'Z'; ch[2]) {
    ascii_map[[3]] = static_cast<int>(ch);
}

Drag options to blanks, or click blank then click option'

A<=

B++

Cch

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using < code < 'Z' > causes 'Z' to be excluded.

Using decrement operator -- instead of increment.

Using wrong variable as map key.

The loop runs while ch is less than or equal to 'Z', increments ch with ++, and uses ch as the key in the map.