PHP if else - 正确使用“else”

Question

A professor told me long ago to use else when "chaining" multiple conditions in a series (I was still learning). Now that I've been tinkering with several frameworks and CMS years later, I find it quite amusing that what I was taught to do isn't necessarily so.

I was taught to use else in between a series of conditions:

function double(param){
    if(param==1){
        return param+=1;
    }
    else 
    if(param==2){
        return param+=2;
    }
    else{
        return false;
    }
}

Nowadays, I seem to see this, which I was warned long ago NOT to do:

function double(param){
    if(param==1){
        return param+=1;
    }
    if(param==2){
        return param+=2;
    }
    return false;
}

This sample code might not work, but the idea is there: Is it necessary to use else in between every condition? If so (or not so), what should I look out for when using either way? There must be something that caused my professor to tell me such thing.

Answer 1

It is not necessary to use else, as the control flow returns from the function immediately at the point of the return keyword.

Further, I find using else when there is a return unnecessarily confusing, and so would prefer alternative 2 in all cases.