Constructor function in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a constructor in Solidity.

Blockchain / Solidity

contract MyContract {
    [1]() {
        // constructor code
    }
}

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

Aconstructor

Bfunction

Cinit

Dsetup

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'function' instead of 'constructor' to declare the constructor.

Naming the constructor like a regular function.

The constructor keyword defines the constructor function in Solidity.

2fill in blank

medium

Complete the code to initialize the state variable in the constructor.

Blockchain / Solidity

contract MyContract {
    uint public value;
    constructor(uint _value) {
        value = [1];
    }
}

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

Avalue

B_val

C_value

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that is not declared as a parameter.

Assigning the state variable to itself.

The constructor parameter is named _value, so we assign it to the state variable value.

3fill in blank

hard

Fix the error in the constructor declaration for Solidity version 0.8+.

Blockchain / Solidity

contract MyContract {
    uint public value;
    [1](uint _value) {
        value = _value;
    }
}

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

Aconstructor

Bfunction MyContract

Cfunction constructor

DMyContract

Attempts:

3 left

💡 Hint

Common Mistakes

Using the contract name as constructor function name.

Including the 'function' keyword with constructor.

Since Solidity 0.8, constructors use the constructor keyword without the function keyword.

4fill in blank

hard

Fill both blanks to create a constructor that sets two state variables.

Blockchain / Solidity

contract MyContract {
    string public name;
    uint public age;
    constructor(string memory [1], uint [2]) {
        name = _name;
        age = _age;
    }
}

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

A_name

Bname

C_age

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Using state variable names as parameter names causing confusion.

Not matching parameter names with those used in the constructor body.

The constructor parameters are named _name and _age to initialize the state variables.

5fill in blank

hard

Fill all three blanks to create a constructor that initializes three state variables.

Blockchain / Solidity

contract MyContract {
    string public title;
    address public owner;
    uint public amount;
    constructor(string memory [1], address [2], uint [3]) {
        title = _title;
        owner = _owner;
        amount = _amount;
    }
}

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

A_title

B_owner

C_amount

Downer

Attempts:

3 left

💡 Hint

Common Mistakes

Using state variable names instead of parameter names in the constructor signature.

Mismatching parameter names and assignments.

The constructor parameters _title, _owner, and _amount initialize the respective state variables.