I've noticed in various smart contract tutorials that different versions of Solidity are declared at the top. I would assume that you would just use the latest but I've noticed that certain contracts seem to work on one platform don't work on another i.e. deploying the same contract via Remix & MetaMask vs Mist?
Choosing Solidity Version – How to Tell Which Version of Solidity to Use for Contract Deployment
metamaskmistremixsolidity
Related Solutions
Click on Environment input and select JavaScriptVM.
You will see the list of 5 accounts with a balance of 100 Ether each.
Enable new EVM features by adding Byzantium to the config section of your genesis.json:
"config": {
"chainId": 1234,
"homesteadBlock": 0,
"eip155Block": 0,
"eip158Block": 0,
"eip160Block": 0,
"byzantiumBlock": 0
},
Thanks to @chriseth, of Solidity, for helping find this
Best Answer
It's a safety feature.
It might help to think of the
solccompiler as a possible source of defects. It's a way of stating the version of compiler that was used in development and testing.Consider a situation in which a team has conducted painstaking testing at great expense. Then, a series of unfortunate circumstances leads to a compile using a newer compiler. They put it into production with the mistaken belief that it was thoroughly tested, but in reality, it's different and broken. Oops!
The compiler will throw an error if it doesn't match what the source file asks for.
In my opinion, the ^ notation is convenient for informal development. The precise notation is required before extensive testing or release.
It basically says "this code was compiled with 0.4.11" and people can compile the source themselves and see that it matches exactly. Implicitly, if the version that was tested was compiled with something else, then "this" bytecode wasn't really tested at all.
Hope it helps.