Does return stop a loop?

Suppose I have a loop like this:

for (var i = 0; i < SomeArrayOfObject.length; i++) {

  if (SomeArray[i].SomeValue === SomeCondition) {

     var SomeVar = SomeArray[i].SomeProperty;
     return SomeVar;
  }
}

Quick question: does the return stop the execution of the loop in and of itself?

Yes, return stops execution and exits the function. return always** exits its function immediately, with no further execution if it's inside a for loop.

It is easily verified for yourself:

function returnMe() {
  for (var i = 0; i < 2; i++) {
    if (i === 1) return i;
  }
}

console.log(returnMe());

** Notes: See this other answer about the special case of try/catch/finally and this answer about how forEach loops has its own function scope will not break out of the containing function.

In most cases (including this one), return will exit immediately. However, if the return is in a try block with an accompanying finally block, the finally always executes and can "override" the return in the try.

function foo() {
	try {
		for (var i = 0; i < 10; i++) {
			if (i % 3 == 0) {
				return i; // This executes once
			}
		}
	} finally {
		return 42; // But this still executes
	}
}

console.log(foo()); // Prints 42

This code will exit the loop after the first iteration in a for of loop:

const objc = [{ name: 1 }, { name: 2 }, { name: 3 }];
for (const iterator of objc) {
  if (iterator.name == 2) {
    return;
  }
  console.log(iterator.name);// 1
}

the below code will jump on the condition and continue on a for of loop:

const objc = [{ name: 1 }, { name: 2 }, { name: 3 }];

for (const iterator of objc) {
  if (iterator.name == 2) {
    continue;
  }
  console.log(iterator.name); // 1  , 3
}

The return statement stops a loop only if it's inside the function (i.e. it terminates both the loop and the function). Otherwise, you will get this error:

Uncaught SyntaxError: Illegal return statement(…)

To terminate a loop you should use break.

Yes, once the return statement is executed, the entire function is exited at that very point.

Just imagine what would happen if it did not and continued looping, and executing that return statement each time? It would invalidate it's meaning of returning a value when you think about it.

The answer is yes, if you write return statement the controls goes back to to the caller method immediately. With an exception of finally block, which gets executed after the return statement.

and finally can also override the value you have returned, if you return inside of finally block. LINK: https://stackoverflow.com/questions/15225819/try-catch-finally-return-clarification

Return Statement definition as per:

Java Docs:

> a return statement can be used to branch out of a control flow block > and exit the method

MSDN Documentation:

> The return statement terminates the execution of a function and > returns control to the calling function. Execution resumes in the > calling function at the point immediately following the call.

Wikipedia:

> A return statement causes execution to leave the current subroutine > and resume at the point in the code immediately after where the > subroutine was called, known as its return address. The return address > is saved, usually on the process's call stack, as part of the > operation of making the subroutine call. Return statements in many > languages allow a function to specify a return value to be passed back > to the code that called the function.

"return" does exit the function but if you want to return large sums of data, you can store it in an array and then return it instead of trying to returning each piece of data 1 by 1 in the loop.