SPDX license and pragma version in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the SPDX license identifier.

Blockchain / Solidity

// SPDX-License-Identifier: [1]
pragma solidity ^0.8.0;

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

AMIT

BGPL-3.0

CApache-2.0

DBSD-3-Clause

Attempts:

3 left

💡 Hint

Common Mistakes

Using a license identifier that is not recognized by SPDX.

Forgetting to include the SPDX license line at the top of the file.

The SPDX license identifier MIT is commonly used to specify the license of the Solidity file.

2fill in blank

medium

Complete the code to specify the Solidity compiler version pragma.

Blockchain / Solidity

pragma solidity [1]0.8.17;

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

A>=

B~

C^

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong symbol that allows incompatible compiler versions.

Omitting the pragma version line.

The caret symbol ^ means the compiler version can be 0.8.17 or higher but less than 0.9.0.

3fill in blank

hard

Fix the error in the SPDX license identifier line.

Blockchain / Solidity

// SPDX-License-Identifier: [1]
pragma solidity ^0.8.0;

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

AMIT License

BMIT

Cmit

DMIT-License

Attempts:

3 left

💡 Hint

Common Mistakes

Writing the license name in lowercase.

Adding extra words like 'License' or hyphens.

The SPDX license identifier must be in uppercase and exactly MIT without extra words or hyphens.

4fill in blank

hard

Fill both blanks to specify a license and a compatible pragma version.

Blockchain / Solidity

// SPDX-License-Identifier: [1]
pragma solidity [2]0.8.12;

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

AApache-2.0

B~

C^

DGPL-3.0

Attempts:

3 left

💡 Hint

Common Mistakes

Using an invalid license identifier.

Using a wrong symbol for the pragma version.

The license Apache-2.0 is valid and the caret ^ allows compatible compiler versions starting from 0.8.12.

5fill in blank

hard

Fill all three blanks to specify the SPDX license, pragma version, and a fixed compiler version.

Blockchain / Solidity

// SPDX-License-Identifier: [1]
pragma solidity [2]0.8.10;
pragma solidity [3]0.8.10;

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

AGPL-3.0

B>=

C==

DMIT

Attempts:

3 left

💡 Hint

Common Mistakes

Using invalid SPDX license strings.

Using incorrect symbols for pragma version constraints.

The SPDX license is MIT. The first pragma uses >= to allow compiler versions 0.8.10 or higher, and the second pragma uses == to fix the compiler version exactly at 0.8.10.