Understanding console.log() within functions vs. using return in JavaScript?

MatthewWalton
October 29, 2024
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0 votes
2 Answers

I’m learning about functions in JavaScript and I’m confused about the role of console.log() and return.

function reusableFunction() {
  console.log("Hi World");
}

reusableFunction();

I understand this function logs "Hi World" to the console. My questions are:

Why doesn’t this function need a return statement? I’ve seen other functions that are used return to send values back. Is console.log() doing something similar?
Why do we call the function with just reusableFunction(); instead of console.log(reusableFunction());? When would I use the second way of calling the function?

I’m trying to understand the fundamental difference between displaying something in the console console.log() and returning a value from a function. Can you explain this with clear examples and perhaps point me to some resources for further learning?

I tried reading Documents like MDN, JS, and Google Developer Docs. I even did a Google Search and kept getting the basics. It answered my question. I just simply want to know when you know to use a return statement in your functions and when to console.log() and then call the function, like this console.log(reusableFunction()) . I understand what console.log() is what the return statement is and the difference between both.

Answers

- LeftBrain
- October 29, 2024 at 7:23 pm
- 0 votes
0
To answer #1:
The function itself simply does not return a value. That is an option for a function, to do some processing on some data and return the result, or a function can just do some processing and that’s it.

I think an analogy could be the difference between

Going to the post office to deliver a letter (no return value)
vs.
Going to the post office to pick up a package and do something with that package at home

#2
When you write Console.Log(reusableFunction()), you are simply combining these two items together. This would make more sense if ‘reusableFunction()’ were returning a result (as descibed in #1). In this case, it doesn’t really make sense because what you’re saying in essence is
```
Log this value to the console -> {returned value from function, which happens to not really be a value}
```
But, like I mentioned, there is no returned value here. Now, you’re still calling the function, so the log line from within (console.log("Hi World");
) will execute as intended. But, this would be an unorthodox way of achieving this.

I hope this helps.
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- AlwaysSunny
- October 29, 2024 at 7:24 pm
- 0 votes
0
These are the detailed answers to both of your questions. I hope the answer will help you understand and clarify the concepts

Why doesn’t this function need a return statement?

Functions don’t necessarily need a return statement unless they’re supposed to produce a value. Here’s why:
- console.log() is used for outputting information to the console.
- It doesn’t return anything; it just prints to the console.
- Functions that only use console.log() are typically used for side effects
  (likeprinting to the console).
Why call the function with just reusableFunction() instead of console.log(reusableFunction());?
- reusableFunction() calls the function and executes its body.
- console.log(reusableFunction()) would pass the function’s return value itself as an argument to console.log().
- The latter is rarely used unless you want to log the function’s return value.
Fundamental differences between displaying and returning values
1. Displaying values (using console.log()):
- Used for outputting information to the console.
- Doesn’t produce a value that can be assigned to variables.
- Useful for debugging and logging.
1. Returning values:
- Produces a value that can be captured and used elsewhere.
- Can be assigned to variables or returned from functions.
- Allows for function composition and passing data between functions.
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