Solidity Programming Essentials

The assert statement

The assert statement has a similar syntax to the require statement. If it accepts a statement, that should then evaluate to either a true or false value. Based on that, the execution will either move on to the next statement or throw an exception. The unused gas is not returned to the caller and instead the entire gas supply is consumed by assert. The state is reversed to original. The assert function results in invalid opcode, which is responsible for reverting the state and consuming all gas.

The function shown previously has been extended to include an addition to the existing variable. However, remember that adding two variables can result in an overflow exception. This is verified using the assert statement; if it ...