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This lesson is going to be all about loops and iteration using JavaScript in order to do a for loop,

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do while loop while loop and break and continue are that are available within the loops.

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So what JavaScript loops do is they allow you to run multiple iterations and you can set the parameters.

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One thing to avoid with loops is infinite loop.

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So you don't want them to be able to loop forever that will cross the browser.

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So always make sure that you have a way out of your loop.

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And that's the purpose of a loop, is to constantly increment values or numbers and then find a way

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out of the loop.

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So once a condition is met, so for instance, this is a for loop.

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We've got a counter while the counter is less than five, it will continue.

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And then once that condition is no longer true, the loop will break.

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And this is true for all the loops.

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So as you're iterating through the content of a loop, you also have to option to break the loop.

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So you have ability to set a condition to break out of the loop so the break will stop the loop.

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There's also one that's called continue true.

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And then we continue.

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Although this one is not commonly used, it is available, but it's not advice because you might run

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into some problems with testing.

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So there is a challenge for this lesson and that's to create a loop of a counter using all three different

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iteration options.

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So you've got the for loop, we've got the while loop and as well the do while loop.

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There's an example of them.

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So these are all going to output the same thing.

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So each loop has a starting point.

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So setting the counter to zero where looping while the counter is less than five.

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And we also need a way to increase the counter.

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So the counter is incrementing by one.

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So this gives us our way out of the loop.

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So we've got our starting point as well within the while loop or setting X to zero while X is less than

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five.

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And then we're incrementing X within the while as well.

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We've got the do while loop, so we're checking to we're setting the value of it to zero where incrementing

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I with one and then we're doing this while I is less than five.

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So first let's create the most common loop.

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So this is the for loop and this is the one that you're going to encounter the most.

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So setting up our counter at zero.

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This is our starting point for the counter.

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And then next is the condition that we want to meet.

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So we want to loop this while counter is less than five and then we need a way out.

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So we need something different.

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We need a counter updating.

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So that's where we just got that counter updating, incrementing by one.

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And this will give us our way out.

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And I'll just write for Loop and then also add in the value of counter just after that.

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So take a look in the console and we see it starts at zero.

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So this is our starting value.

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We can start it up one as well.

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So that will start at one, two, three, four, and then we can loop while counter is less than six.

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So that means that it's going to break after five.

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So that was one example.

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The other example is this is while loop.

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So let's set our starting points.

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So using X as our starting point, we're going to loop while X is less than five.

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And then this is where the blockquote goes.

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Always make sure that your incrementing X because this is again are way out of the loop and this is

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our while loop.

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And then we can see the value of X.

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And depending on what we're trying to accomplish with your coding, you may choose you may prefer to

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use one looping method over the other.

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And also keep in mind that wherever we're producing the X increment, that's going to affect the value

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of X at the time we're running the code.

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So for placing it before or after, it will make a difference within the output.

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And then lastly, let's do one last loop and this is the do while loop.

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So this is very similar to the while loop and there is actually one important difference.

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So let's set it up and we'll run through it and then we'll see what the difference there is.

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So within the console log.

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So this is the do while and adding in the value of ice so that we can see it.

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And then the condition that's going to break this loop is while AI is less than five.

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So let's try that.

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And you can see that the result is the same thing where if we do the increment of AI afterwards, it's

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going to work the same way as the while loop.

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So the difference here is that if the starting values for the while loop are ten and for the do while

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loop R ten, you're going to see one interesting difference.

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And that means that the do while loop always runs at least one time, whereas the while loop, because

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this condition isn't met, it never runs this block of code because the value of X is ten.

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So if you need to run it at least one time.

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You can use a do while loop, otherwise you could just use a while loop, or if you prefer, you can

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use a for loop, so do try out all three.