How to skip to next iteration in jQuery.each() util?

javascript

callbacks

functions

best-practices

byAnton Shumikhin·Oct 27, 2024

To skip to the next loop iteration in jQuery.each(), simply use return true;. This acts similar to continue in a standard loop.

$.each(array, function(index, value) {
  if (skipCondition) return true; // See ya, going to the next one!
  // Rest of your logic here
});

Keep in mind: return true; takes on the role of a 'loop continue' within the $.each() function.

'return true' vs 'return false'

One key nuance in jQuery.each() is understanding the difference between return true; and return false;. return true; will skip the current iteration and move on to the next one, while return false; halts the entire loop operation, mid-track!

$.each(array, function(index, value) {
  if (shouldStopLoop) return false; // Stop! Hammer time.
  if (skipCondition) return true; // Next round, please.
});

Understanding truthiness in JavaScript

Embrace the concept of JavaScript's truthiness to better manage your loops. With jQuery.each() any non-false value returned by the callback will trigger the next iteration. This means values like 1, 'non-false', or {} will mirror the behavior of return true;.

$.each(array, function(index, value) {
  if (myUniqueCondition) return 'non-false'; // This will sneak past and skip to next iteration too!
  // Rest of your logic here...
});

Guarding against common errors

A few mistakes can sneak into your .each() iterations if you're not careful. Know that break isn't supported by jQuery.each(). Attempting to use it will cause a cacophony of errors. Also, stay sharp with your conditional expressions to avoid any unintentional march-past of iterations.

Avoidable pitfalls and good practices

To ensure a glitch-free performance, keep in mind some useful tips:

Don't overload conditionals: Having too many can churn performance and make your code look like a battlefield.
Avoid mid-loop modifications: Changing array elements during iteration can lead to unexpected tour de loops.
Keep logic simple: Your callback within .each() should be as simple as possible. Remember, simplicity is genius.

Advanced strategies for enhanced control

For those looking to master their loops, here are some tips:

Consider using $.grep() before .each() to pre-filter values you would otherwise skip using return true;.
Store return values from each callback in an external array for post-loop manipulation. Why waste good data?
If skipping isn't a priority, consider switching over to .map() for transformation operations. After all, variety is the spice of life!