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I'm trying to learn JS from Codecademy. I'm doing this excercise.

Can someone please tell me why return is used instead of console.log()? I don't fully understand how return works.

Sebastian Simon
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T JY
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5 Answers5

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console.log is useful for debugging purposes, but actually can't accomplish anything as far as affecting the surrounding code or application.

return is a way of "returning" a value generated by a function to the place it was called from. Think of it as giving a value to that function.

example:

 function retFive(){
   return 5;
 }

 var x = 37 + retFive();
console.log(x); //prints out 42

hope that helps!

dgeare
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1

A function in code is really no different from a math function. Think about it this way:

f(x) = x+1

Which would "return" something based on the input of x.

So f(1) = 2 because f(1) returns the value of 1+1.

Putting that into Javascript:

function f(x){
    return x+1;
}

allows us to do this:

var y = f(1);

Now the value of y is 2.

Without a return, we wouldn't be able to assign the value to y.

console.log() really does nothing. It just logs something to the console to view or debug values.

Christopher Schneider
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1

return has pretty much the same behavior as it does in other languages.

From the return MDN

When a return statement is called in a function, the execution of this function is stopped. If specified, a given value is returned to the function caller. If the expression is omitted, undefined is returned instead.

What this basically means is that when you call a function foo() that has a statement like return 1; it will have the value of 1 so: var bar = foo(); // bar = 1

function foo() {
    return 1;
}
var bar = foo(); // bar = 1

console.log() can be confusing if you're running the program in the console, it prints the value to the console so if our function foo from before was function foo() { console.log(1); } our var bar = foo(); would actually set bar to undefined.

function foo() {
    console.log(1);
}
var bar = foo(); // bar = undefined

console.log() MDN

Patrick Barr
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Return Is used to return a value from a function.

function foo(){
    return 1;
}

console.log(foo()); //1

Useful when you have a function that does an operation that needs to return a value, and saves up space so you don't have to use a variable. It's generally just a more professional way of coding.

Programah
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Without answering about that exercise specifically, the purpose of a return statement is to pass information from one function call to another. This information can be anything - an object, a string, a number, and can have any purpose, whether that be to return information about whether the function was successful or not, or to do a calculation and return the answer so another function can use it.

Console.log() simply prints out whatever you pass in as a parameter to the console, which can change depending on your context. It doesn't have anything to do with relaying information from one part of your program to another.

josephmbustamante
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