In Solidity, understanding the differences in gas consumption between storage and memory is crucial for optimizing smart contracts. Each data location has distinct characteristics that affect gas costs during execution.

Gas Costs Overview

• Storage:
  storage is significantly more expensive than writing to memory. The cost for storing a new variable is 20,000 gas, while rewriting an existing variable costs 5,000 gas.
• Reading from storage costs 200 gas per read operation.
• Data in storage persists between function calls, making it suitable for state variables.

Sample Code Demonstrating Gas Consumption

Below is an example that illustrates the differences in gas consumption between storage and memory:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract GasConsumptionExample {
    // State variable stored in storage
    uint256[] public storageArray;

    // Function to add a value to the storage array
    function addToStorage(uint256 value) public {
        storageArray.push(value); // This modifies the storage
    }

    // Function to demonstrate memory usage
    function createMemoryArray(uint256 length) public pure returns (uint256[] memory) {
        // Creating a dynamic array in memory
        uint256[] memory memoryArray = new uint256[](length);
        for (uint256 i = 0; i < length; i++) {
            memoryArray[i] = i + 1; // This modifies the memory
        }
        return memoryArray; // Returning the memory array
    }
}

Conclusion

In summary, gas consumption in Solidity differs significantly between storage and memory. While storage is more expensive due to its permanence and the costs associated with writing and reading, memory offers a cheaper alternative for temporary data. Understanding these differences is essential for optimizing gas costs and improving the efficiency of smart contracts.