[Solved] Does a statement after return encounters even execute the statement after it

Question

The Law of Excluded Middle is incredibly useful for formal reasoning about if statements. The two choices that you have in your code are as follows:

n is equal to 1, and
n is not equal to 1.

There is no third “middle” state in this logic.

Now let’s go back to your code, and see what happens depending on the value of n. When it is 1, your code returns 1. When n is not one, your code returns a result of some calculation.

In order for printf("Hello") to be reached, n needs to be equal to one and not equal to one at the same time (i.e. n==1 && n!=1 must be true). The law of excluded middle lets you mathematically prove that this expression is false for all values of n, meaning that the printf line is unreachable under any circumstances. Optimizing C compilers will issue a warning, and remove this “dead code” from the executable that they generate.

Accepted Answer

The Law of Excluded Middle is incredibly useful for formal reasoning about if statements. The two choices that you have in your code are as follows:

n is equal to 1, and
n is not equal to 1.

There is no third “middle” state in this logic.

Now let’s go back to your code, and see what happens depending on the value of n. When it is 1, your code returns 1. When n is not one, your code returns a result of some calculation.

In order for printf("Hello") to be reached, n needs to be equal to one and not equal to one at the same time (i.e. n==1 && n!=1 must be true). The law of excluded middle lets you mathematically prove that this expression is false for all values of n, meaning that the printf line is unreachable under any circumstances. Optimizing C compilers will issue a warning, and remove this “dead code” from the executable that they generate.