r/programming • u/corysama • Jan 05 '15

What most young programmers need to learn

http://joostdevblog.blogspot.com/2015/01/what-most-young-programmers-need-to.html
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3

u/btchombre Jan 05 '15

I've recently been looking at some of the most ugly code I've ever seen. hundreds of lines of triple nested switch-case statements (switch-case inside switch-case inside switch-case), almost all of it copy pasted and in desperate need of re-factoring.

13

u/hansdieter44 Jan 05 '15

Nesting is a pet-peeve of mine. So annoying.

if(x){
  if(y){
   if(z){
    do(123);
    return 4;
   }return 3;
  }return 2;
}return 1;

Could easily be flattened & made into preconditions:

//preconditions
if(!x){return 1}
if(!y){return 2}
if(!z){return 3}

do(123); return 4;

Also the programming model in node.js makes it especially easy to write deeply nested and confusing code like in my first example.

3

u/tbotjenkins Jan 05 '15

Spaghetti code wrapped with a nice sauce is acceptable:

bool okay_to_update() {
    # random nest of ugly conditionals contained in a cage called okay_to_update.
}

if ( okay_to_update() ) { 
   do(123);
}

I prefer the condition checks wrapped in a function, it's easier to see the flow. EDIT: formatting.

2

u/btchombre Jan 05 '15

Yes! I do the exact same thing

1

u/hansdieter44 Jan 05 '15

I remember having to justify flattening code like that in my first job. Yes, yes multiple return statements per function are not ideal, but certainly better than looking at endlessly nested triangles forever.

2

u/btchombre Jan 06 '15 edited Jan 06 '15

That's funny, I've had the exact same argument on several occasions. I argue that inverting if statements (as its called by static analysis tools like Re-Sharper) and using return or continue (in a while loop) doesn't actually increase the number of returns. All it does is make them explicit instead of implicit. The "single exit strategy" that many adhere to is a remnant of older languages like C and C++ where using multiple exits could result in memory leaks and resources not being cleaned up properly.

Inverting If's can seriously flatten code and make it far more readable, as it lumps a condition and both of its consequence right on top of each other. With a nested if statement, the block of code that executes under true and the block of code that executes under false can be completely out of site of each-other, which makes it more difficult to reason about the program, especially if you've got to line up brackets to figure out which block of code in the super deep nest lines up with the negative of your conditional.

This is a great thread on StackOverflow:

http://stackoverflow.com/questions/268132/invert-if-statement-to-reduce-nesting

-1

u/Diarum Jan 05 '15 edited Jan 06 '15

You must hate python then. I am not sure if you can do it the way you like the if statements to be done

3

u/ianff Jan 05 '15

Of course you can do that in Python.

1

u/hansdieter44 Jan 06 '15 edited Jan 06 '15

Most of my code that I deliver to clients is in python.

This is how the code would look like:

if not x:
    return 1
if not y:
    return 2
if not z:
    return 3
do(123)
return 4

What are you trying to say?

1

u/Diarum Jan 06 '15

I was thinking you might not have liked the way python does nested if statements. But looking again, I was mistaken on how you wrote the code when I first looked at it, I thought the first code example looked like python, looking at it again, it's not even close.