Ethereum Opcodes: A Comprehensive List
The Ethereum network is built on the Solidity programming language, which allows developers to build smart contracts and decentralized applications (dApps) on top of the Ethereum blockchain. However, the underlying infrastructure also provides access to extensive information about the current opcodes used by the network.
In this article, we will provide an overview of the current opcodes available on Ethereum, including their definitions, types, and examples.
What are opcodes?
Opcodes are instructions that make up a transaction or contract function call on the Ethereum blockchain. They are essentially a set of binary code that represents the action performed by the program. In other words, opcodes are the “syntax” of Ethereum.
Ethereum Opcodes Library
You can use the following methods to access the current list of opcodes:
- Ethereum API: The official Ethereum API provides a list of available opcodes in the ethops module, which can be accessed using the ethops.getOpcodes() function.
- Solidity Code Snippets: Online resources such as Slideshare and GitHub provide code snippets that show the current opcodes used by Solidity programs on the network.
- Ethereum Blockchain Explorer: The Ethereum blockchain explorer provides a web interface where you can view the current opcodes for each block on the network.
Current Opcode List
Here are some of the current opcodes available in Ethereum:
0x00: Initialize the state of a contract or smart contract
0x01: Call a function of a contract or smart contract
0x02: Set the value of a variable in a contract or smart contract
0x03: Get the value of a variable in a contract or smart contract
0x04: Jump to another block in the network
0x05: Unwind an array of opcodes
0x06: Call a function that tests if a condition is true
0x07: Call a function that tests if a condition is false
0x08: Get the number of arguments passed to a function
0x09: Set the number of arguments passed to a function
0x10: Get the current block hash
0x11: Get the current block timestamp
0x12: Get the current value of a contract or smart contract variable
0x13: Get the value of an array element of a contract or smart contract
Here is an example code snippet that uses Solidity to display the opcode list for all functions and variables:
pragma solidity ^0,8,0;
contract exampleContract {
function foo() public pure returns (bool) {
return true;
}
function bar(uint256 a, uint256 b) public returns (uint256) {
return a + b;
}
}
Using the Ethereum API module “ethops” to get a list of all the opcodes for functions and variables:
pragma rigidity ^0,8,0;
contract exampleContract {
function foo() public pure returns (bool) {
return true;
}
function bar(uint256 a, uint256 b) public returns (uint256) {
return a + b;
}
}
contract EthereumAPIExample {
function getOpcodes() public pure returns (uint256[]) {
// Get a list of opcodes for all functions and variables
uint256[] memory opcodes = new uint256[](2);
opcodes[0] = 0x01; // foo()
opcodes[1] = 0x02; // bar(uint256a, uint256b)
return opcodes;
}
}
Please note that the “ethops.getOpcodes()” function will only return the opcodes used in the Solidity code of the contract being tested. Furthermore, this list may not be complete and may change over time as new opcodes are added to the Ethereum network.
Conclusion
Ethereum opcodes provide a basic level of functionality for smart contracts and dApps on the blockchain.