Scope of variables in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable inside the main function.

C++

int main() {
    int [1] = 10;
    return 0;
}

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

Anumber

Bcout

Cmain

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using a keyword as a variable name.

Using function names as variable names.

The variable name inside main should be a valid identifier like number.

2fill in blank

medium

Complete the code to print the value of the local variable inside the function.

C++

#include <iostream>
using namespace std;

void show() {
    int x = 5;
    cout << [1] << endl;
}

int main() {
    show();
    return 0;
}

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

Ax

By

Cz

Dcout

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to print a variable not declared in the function.

Using variable names not declared anywhere.

The variable x is declared inside show() and can be printed there.

3fill in blank

hard

Fix the error by completing the code to access the global variable inside the function.

C++

#include <iostream>
using namespace std;

int [1] = 100;

void printGlobal() {
    cout << [1] << endl;
}

int main() {
    printGlobal();
    return 0;
}

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Anum

Bvalue

Cx

DglobalVar

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the global variable declaration and usage.

Trying to access a variable not declared globally.

The global variable name must be the same in declaration and usage. Here, globalVar is used.

4fill in blank

hard

Fill both blanks to declare a variable inside a block and print it.

C++

#include <iostream>
using namespace std;

int main() {
    {
        int [1] = 20;
        cout << [2] << endl;
    }
    return 0;
}

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

AblockVar

CmainVar

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for declaration and printing.

Trying to access the variable outside the block.

The variable declared inside the block is blockVar, which is also printed inside the same block.

5fill in blank

hard

Fill all three blanks to declare a global variable, shadow it inside main, and print both values.

C++

#include <iostream>
using namespace std;

int [1] = 50;

int main() {
    int [2] = 100;
    cout << ::[3] << endl; // global
    cout << [2] << endl; // local
    return 0;
}

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

Acount

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for global and local variables.

Not using :: to access the global variable inside main.

The global variable count is declared outside main. Inside main, a local variable count shadows the global one. Using ::count accesses the global variable.