if-else or early return

Question

Sometimes I like to use early return statements to prevent nesting if statement, which I find makes for less readable code.

I am wondering if there is any objective or overwhelming general consensus as two which of the following patterns is better practice? I don't think this is a subjective question, since what I am really asking is there a near objective preference.

void func() {
    if (a) {
        do b
    }    
    else {
        do c
    }
}

or

void func() {
    if (a) {
        do b
        return;
    }

    do c
}

Answer 1

I would opt for the first version. I was actually given a lengthy explanation several years ago regarding this.

The two examples, as your wrote them now, are functionally identical. If the a condition be true, then the logic in the first if condition will execute, and the function will return. However, have a closer look at the second scenario:

void func() {
    if (a) {
        do b
        return;
    }

    do c
}

Right now, should the first if fire, the function would return, otherwise c would execute. However, consider that at some point down the line a programmer decides to refactor the method for some reason. If he were to take out the return statement, then the logic for c would also execute if a were true. This may seem far-fetched, but it could happen more easily than you might think. On the other hand, if you use a full if-else, then even a refactor of the if condition would never result in the c logic evaluating at the same time.

Answer 2

Frankly, I recommend the second one.

• 1. The second is more clear to understand
• 2. When some else modify the code more easy to understand is the first place. Maybe the first is more clear in math but not in human being.

Answer 3

The first is better. Simply put,it helps another developer to understand that c compiles because the condition is false. It also prevents other people from making damaging changes to your code. That said,they are both correct and would both work just fine