August 2018
Intermediate to advanced
404 pages
11h 19m
English
Content preview from Ethereum Cookbook
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How it works...
EVM is the runtime environment for Ethereum smart contracts. Contracts running inside EVM have no access to the network, filesystem, or other processes. This is because of the isolated and sandboxed nature of EVM.
The first line in this smart contract tells us that the source code is written for compiler version 0.4.21 or anything newer (such as <0.5.0) that does not break any functionality. The pragma keyword is used because pragmas are instructions for the compiler about how to treat the source code.
The line string textToPrint = "hello world"; declares a state variable called textToPrint and assigns a value to it. You can think of it as a slot in a database that can be queried and altered by calling the functions in the ...