2.20 Control Structures

These are fundamental to any programming language because there is a control flow to the sequence of instructions specified in the high-level language that get translated into machine code by the compiler.

In the case of Solidity, the control structures supported are if, else, while, do, for, break, continue and return. These are very similar to the ones found in any programming language. Although are some differences in Solidity: paranthesis for example cannot be omitted for conditionals that some of the other languages support, however curly braces can be omitted around single statement bodies for such conditionals.

Also note that there is no type conversion from a non-boolean to a boolean type. As an example, if(1) is not allowed in Solidity because 1 is not convertible to the boolean true, which is supported by some of the other languages.

So control structures play a critical role in the security analysis of smart contracts whether you're doing a manual review or whether you're writing a tool to pass the Solidity smart contract. These are some things to be understood really well because that's how control flows, and any analysis depends critically on making sure that the control flow is accurately followed and representative of what really happens at runtime.