foreach not returning expected results

1. Why does forEach return undefined?
2. Does return end forEach?
3. Can forEach return a value?
4. Does return work in forEach?
5. Why is map better than forEach?
6. Why is map faster than forEach?
7. How do I return after forEach?
8. How do you break in forEach?
9. Can you break out of a forEach JavaScript?
10. Is forEach asynchronous?
11. How do you return a value from a loop in JavaScript?
12. What is forEach loop in Java?

Why does forEach return undefined?

Well, the forEach() method doesn't actually return anything (undefined). It simply calls a provided function on each element in your array. This callback is allowed to mutate the calling array. Meanwhile, the map() method will also call a provided function on every element in the array.

Does return end forEach?

'return' doesn't stop looping

The reason is that we are passing a callback function in our forEach function, which behaves just like a normal function and is applied to each element no matter if we return from one i.e. when element is 2 in our case. ... If you need such behavior, the forEach() method is the wrong tool.

Can forEach return a value?

forEach() executes the callbackFn function once for each array element; unlike map() or reduce() it always returns the value undefined and is not chainable. The typical use case is to execute side effects at the end of a chain. Note: There is no way to stop or break a forEach() loop other than by throwing an exception.

Does return work in forEach?

If we dissect the forEach, we see that each element is sent to a callback function. So the callback function does return, but to the forEach. ... There is no way to stop or break a forEach() loop other than by throwing an exception.

Why is map better than forEach?

The first difference between map() and forEach() is the returning value. The forEach() method returns undefined and map() returns a new array with the transformed elements. Even if they do the same job, the returning value remains different.

Why is map faster than forEach?

Final Thoughts. You can use both map() and forEach() interchangeably. The biggest difference is that forEach() allows the mutation of the original array, while map() returns a new array of the same size. map() is also faster.

How do I return after forEach?

Return Value of forEach in JavaScript

1. forEach executes the callback function once for each array element.
2. It always returns undefined.
3. It does not mutate the array, but the callback can if programmed to do so.
4. forEach is not chain-able like map, reduce or filter.

How do you break in forEach?

How to Break Out of a JavaScript forEach() Loop

1. Use every() instead of forEach() ...
2. Filter Out The Values You Want to Skip. ...
3. Use a shouldSkip Local Variable. ...
4. Modify the array length.

Can you break out of a forEach JavaScript?

There's no built-in ability to break in forEach . To interrupt execution you would have to throw an exception of some sort. eg. JavaScript exceptions aren't terribly pretty.

Is forEach asynchronous?

forEach Asynchronous? It is not asynchronous. It is blocking. Those who first learned a language like Java, C, or Python before they try JS will get confused when they try to put an arbitrary delay or an API call in their loop body.

How do you return a value from a loop in JavaScript?

1. The return statement immediately exits a function, returning the value of the expression that follows it. If you use a return statement in a loop without some sort of conditional like that it will preform the first pass and then exit. ...
2. Thanks Useless Code after looking into this a bit deeper I see where I was mistaken.

What is forEach loop in Java?

Java forEach loop

Java provides a new method forEach() to iterate the elements. It is defined in Iterable and Stream interface. It is a default method defined in the Iterable interface. Collection classes which extends Iterable interface can use forEach loop to iterate elements.