WEBVTT

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In previous video, we have talked about and described how up works and now it's time to consider other

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types of loops which are wild and do while while Loop does actually almost the same work as for a loop.

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The main difference between them is in Syntex, as I remember.

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In case of rollup, we had three statements in parentheses, initialization condition and increment

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or decrement.

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As for the while the counter is created outside it, then we need to write words while inside parentheses

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we have only the condition.

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And inside the Brice's, we have a block of code where we can put the increment or the of the counter,

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so it's right, cancel that log.

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I and then I plus plus reload the page and we have hear numbers from zero to 10 because in while we

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had condition I is less than or equal to 10.

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OK, as I see it plus plus is written after the council.

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But if we place it before council then we will get the numbers from one to 11.

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It seems a little bit strange.

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So let me explain what has happened here, as you know, in case of a look at the value of counter was

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updated after the execution of the code block.

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In this case, we see that eye is set as zero.

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It means that we have zero is less than or equal to that in condition.

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Then JavaScript engine continues reading codes line by line.

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It says E-Plus Plus and updates its value from zero to one.

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And that's the reason why we got one as the first number instead of zero.

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And also, that's why the result ends with 11, when it becomes 10, then the condition is true.

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But because of that we have a plus plus before council log that the value of AI becomes 11 for the last

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iteration.

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Makes sense.

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All right, this will make us unexpected results when we use while loop with a race in practice.

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Let's see what I mean, create a right of colors and insert here some colors, light red than green

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and blue.

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And use wire look to output the items of the array, set the counter as zero that creates while.

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Weather condition is less than colors that length.

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And inside the coal prices.

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Run in council colors, I and then I plus plus.

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Without and you, we have our colors in order.

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But if we place a plus plus before council, that log.

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That.

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You said that the first item escaped and after the last item we have identified.

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The reason is, say, for the last iteration, I became four and we know that item with index number

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four doesn't exist in the array and that's why we got undefined.

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All right, the next that I want to show you is do I loop the do loop is like the wire loop, but it

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executes the block of code once before, checking if the condition is true or false.

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If it's true, then to wire loop will continue looping as long as the condition is true.

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At first we write the key do.

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Then inside the Culebra we need to write block of code.

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Right, again, cost of log.

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Caldas, I.

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And then the increment I plus plus.

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After that, we have to right to keep keyboard while with its condition.

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Let's reload the page and again, we have colors from the air, right, as we said, in case of four

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and while loops the execution of block of code would not start and execute if the conditions are false.

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But in case of develop, it doesn't matter whether condition is true or false.

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The first iteration will be always executed.

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So if we make your condition false and right eye is greater than color length, then we will get all

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of the first item from the array, which is white.

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So remember that in case of the wallop, at first the code is executed and that the condition is checked,

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if it's true, the loop is continuing to work accordingly before the condition becomes false.

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This is the main difference between life and death.

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Wallach's.

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All right, so in this lecture, we have learned a while and two while loops are and how they work,

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let's move on.