{"nextChapter":{"id":248,"slug":"functions","hindi_slug":"functions","order":5,"is_free":false,"lchapter_content":{"id":259,"name":"Functions","description":null,"image":null,"lchapter_id":248,"language_code":"EN"}},"prevChapter":{"id":246,"slug":"variables-and-data-types","hindi_slug":"variables-and-data-types","order":3,"is_free":false,"lchapter_content":{"id":256,"name":"Variables and Data Types","description":null,"image":null,"lchapter_id":246,"language_code":"EN"}},"nextTopic":{"id":946,"slug":"kotlin-break-continue-statements","hindi_slug":"kotlin-break-continue-statements-hindi","order":4,"lcourse_id":63,"lchapter_id":247,"is_free":false,"ltopic_content":[{"id":964,"name":"Kotlin Break and Continue Statements (With Examples)","description":null,"image":null,"ltopic_id":946,"language_code":"EN","faq_title":null}]},"prevTopic":{"id":944,"slug":"kotlin-for-loop","hindi_slug":"kotlin-for-loop-hindi","order":2,"is_free":false,"ltopic_content":[{"id":956,"name":"for Loop in Kotlin (Examples, Range, Index, Uses)","description":null,"image":null,"ltopic_id":944,"language_code":"EN","faq_title":"Kotlin for Loop FAQs"}]},"topic":{"id":945,"slug":"kotlin-while-do-while-loops","hindi_slug":"kotlin-while-do-while-loops-hindi","lcourse_id":63,"lchapter_id":247,"order":3,"is_free":false,"ltopic_content":[{"id":963,"name":"Kotlin while & do while Loops (With Examples)","description":null,"image":null,"ltopic_id":945,"language_code":"EN","faq_title":"Kotlin while & do while Loops FAQs"}],"lchapter":{"id":247,"slug":"control-flow","hindi_slug":"control-flow","order":4,"is_free":false,"lchapter_content":{"id":258,"name":"Control Flow"}},"lsubtopics":[{"id":4945,"slug":"introduction-164","hindi_slug":"introduction-hindiss","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":0,"lsubtopic_content":{"id":5017,"name":"Introduction","description":"

In programming, we may need to execute the same code multiple times to solve a problem. We can achieve this by repeating the code repeatedly, which is time-consuming and tedious.

\r\n

The good news is there is a simpler and more efficient way to do it- Loops, which programmers can use in such situations.

\r\n

Loops are used in programming to repeat the same block of code repeatedly until a specific condition is fulfilled. They make computers interesting machines. Suppose you need to print a single statement 100 times without using loops. You might find a way to do it somehow. However, what if you have to print that statement a thousand or a million times? That is where loops come in handy.

\r\n

In this blog, we will discuss the while and do-while loops in Kotlin. We will understand how each of these loops works, their flowcharts, and where and how these loops are used. We will also read about break statements and how break expressions are used in Kotlin programming.

","image":"","lsubtopic_id":4945,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4946,"slug":"kotlin-while-loop","hindi_slug":"Kotlin-while-Loop","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":2,"lsubtopic_content":{"id":5018,"name":"Kotlin while Loop","description":"

A while loop in Kotlin, like in many other programming languages, is a control structure that allows you to repeatedly execute a block of code as long as a specified condition is true.

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Syntax of while Loop in Kotlin

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while (condition) {\r\n    // Code to be executed repeatedly as long as the condition is true\r\n}

\r\n

Here's a more detailed explanation of the components of a while loop in Kotlin:

\r\n

\r\n
while: This is the keyword that marks the beginning of the while loop.
\r\n
\r\n
condition: This is the expression that defines the condition to be checked before each iteration of the loop. If the condition is true, the code block inside the loop will be executed; otherwise, the loop terminates.
\r\n
Code Block: The code block enclosed in curly braces { } is the body of the while loop. This is the code that gets executed repeatedly as long as the condition remains true.

","image":"","lsubtopic_id":4946,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4947,"slug":"how-does-kotlin-while-loop-work","hindi_slug":"How-Does-Kotlin-while-Loop-Work?","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":3,"lsubtopic_content":{"id":5019,"name":"How Does Kotlin while Loop Work?","description":"

A while loop in Kotlin works by repeatedly executing a block of code as long as a specified condition remains true.

\r\n

Here's a step-by-step explanation of how a Kotlin while loop works:

\r\n

\r\n
Initialization:
\r\n

\r\n

You typically start by initializing one or more variables that will be used in the loop. This step is not mandatory, but it's common to set up initial values before entering the loop.

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var i = 1 // Initialize a variable

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\r\n
Condition Check:
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\r\n

The condition specified in the while statement is evaluated. If the condition is true, the loop body is executed. If the condition is false initially, the loop is skipped entirely, and the program continues with the code after the loop.

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while (i <= 5) {\r\n    // Loop body\r\n}

\r\n

\r\n
Loop Body Execution:
\r\n

\r\n

If the condition is true, the code inside the loop body is executed. This is where you place the actions or statements that you want to repeat.

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println(\"Iteration $i\")

\r\n

\r\n
Condition Update:
\r\n

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After executing the loop body, the loop control variable (in this case, i) is typically modified in some way to eventually make the condition false. If you forget to update the control variable, you might create an infinite loop, which runs indefinitely.

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i++ // Increment i to avoid an infinite loop

\r\n

\r\n
Condition Recheck:
\r\n

\r\n

After the loop body is executed and the control variable is updated, the condition is rechecked. If the condition is still true, the loop continues with another iteration; otherwise, the loop terminates, and program execution continues with the code following the loop.

\r\n

\r\n
Repeat:
\r\n

\r\n

Steps 3 to 5 are repeated until the condition becomes false. Once the condition is no longer true, the while loop exits, and the program continues with the code after the loop.

","image":"","lsubtopic_id":4947,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4948,"slug":"flowchart-of-kotlin-while-loop","hindi_slug":"Flowchart-of-Kotlin-while-Loop","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":4,"lsubtopic_content":{"id":5020,"name":"Flowchart of Kotlin while Loop","description":"

$\"Flowchart$

\n","image":"","lsubtopic_id":4948,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4949,"slug":"kotlin-while-loop-example","hindi_slug":"Kotlin-while-loop-Example","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":5,"lsubtopic_content":{"id":5021,"name":"Kotlin while loop Example","description":"

Here's an example of a Kotlin while loop:

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fun main() {\r\n    var count = 1 // Initialize a variable\r\n    while (count <= 5) { // Loop as long as count is less than or equal to 5\r\n\r\n        println(\"Count: $count\")\r\n        count++ // Increment count\r\n    }\r\n    println(\"Loop Finished\")\r\n}

\r\n

Output:

\r\n

Count: 1\r\nCount: 2\r\nCount: 3\r\nCount: 4\r\nCount: 5\r\nLoop Finished

\r\n

In this example:

\r\n

\r\n
We start with the variable count initialized to 1.
\r\n
\r\n
The while loop has the condition count <= 5, so it will continue executing as long as count is less than or equal to 5.
\r\n
\r\n
Inside the loop, we print the value of count and then increment it by 1 with count++.
\r\n
\r\n
The loop will continue until count reaches 6, at which point the condition becomes false, and the loop exits.
\r\n
\r\n
Finally, we print \"Loop Finished\" after the loop has completed.
\r\n

\r\n

The loop runs five times, printing the value of count in each iteration, and then it finishes.

","image":"","lsubtopic_id":4949,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4950,"slug":"kotlin-do-while-loop","hindi_slug":"Kotlin-do-while-Loop","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":6,"lsubtopic_content":{"id":5022,"name":"Kotlin do-while Loop","description":"

The do-while loop in Kotlin is similar to the while loop, but there is one difference. The do-while loop first executes the block of code once before checking the test expression and repeats the loop until the given condition is false.

\r\n

Similar to the do-while loop in Java, Kotlin do-while loop is a control flow statement that executes a specific block of code at least once without evaluating the test condition. Whether it executes the block of code or not depends on the condition at the end of the do-while block.

\r\n

While and do-while loops execute a block of code again and again until the given condition is satisfied. However, the difference between them is the time they check the condition. The while loop checks the condition first, and only if it’s satisfied, it executes the body of the loop and returns to the condition. So, it executes the block of code only when the test condition is evaluated to be true.

\r\n

On the other hand, do-while first executes the code and then evaluates the test condition. So, it executed the code at least once, even if the condition is false.

\r\n

Syntax of the do-while loop

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do {\r\n    // Code to be executed\r\n} while (condition)

\r\n

Here's a step-by-step explanation of how a do-while loop works:

\r\n

\r\n
Code Execution: The code block inside the do { } is executed first, unconditionally, without checking the condition.
\r\n
\r\n
Condition Check: After executing the code block, the condition specified in the while statement is evaluated.
\r\n

\r\n

\r\n
Loop Continuation or Termination: If the condition is true, the loop will continue to execute the code block. If the condition is false, the loop terminates, and the program continues with the code after the loop.
\r\n
Repeat: Steps 1 to 3 are repeated until the condition becomes false. This ensures that the code block is executed at least once, even if the condition is initially false.

","image":"","lsubtopic_id":4950,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4951,"slug":"flowchart-of-do-while-loop","hindi_slug":"Flowchart-of-do-while-Loop","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":7,"lsubtopic_content":{"id":5023,"name":"Flowchart of do-while Loop","description":"

$\"Flowchart$

\n","image":"","lsubtopic_id":4951,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4952,"slug":"kotlin-do-while-example","hindi_slug":"Kotlin-do-while-Example","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":8,"lsubtopic_content":{"id":5024,"name":"Kotlin do while Example","description":"

Here's an example of a do-while loop in Kotlin. In this example, we'll create a simple program that asks the user for a number repeatedly until they enter a negative number, and then it will display the sum of all the positive numbers entered.

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fun main() {\r\n    var sum = 0\r\n    var number: Int\r\n    do {\r\n        print(\"Enter a number (or a negative number to exit): \")\r\n        number = readLine()!!.toInt()\r\n        if (number >= 0) {\r\n            sum += number\r\n        }\r\n    } while (number >= 0)\r\n    println(\"Sum of positive numbers entered: $sum\")\r\n}

\r\n

Output:

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Enter a number (or a negative number to exit): 5\r\nEnter a number (or a negative number to exit): 8\r\nEnter a number (or a negative number to exit): 2\r\nEnter a number (or a negative number to exit): -1\r\nSum of positive numbers entered: 15

\r\n

In this program:

\r\n

\r\n
We initialize sum to 0 to keep track of the sum of positive numbers.
\r\n
\r\n
We declare a number variable to store the number entered by the user.
\r\n
\r\n
The do block contains the code that asks the user for a number, converts it to an integer, and checks if it's positive. If it's positive, it adds the number to sum.
\r\n
\r\n
The while condition is number >= 0, which means the loop will continue as long as the user enters a non-negative number.
\r\n
\r\n
When the user enters a negative number, the loop terminates, and the program displays the sum of all the positive numbers entered.
\r\n

\r\n

The program continues to prompt the user for numbers until a negative number is entered. Then, it calculates and displays the sum of all the positive numbers entered by the user.

","image":"","lsubtopic_id":4952,"language_code":"EN","duration":"00:00:00","instruction":null,"lsubtopic_code":null,"lsubtopic_output":null,"lsubtopic_explanation":null},"lsubtopic_video":null,"lquestions":[],"paused_lsubtopic":null},{"id":4953,"slug":"break-statement-1","hindi_slug":"Break-Statement","lcourse_id":63,"lchapter_id":247,"ltopic_id":945,"type":"content","quiz_type":1,"order":9,"lsubtopic_content":{"id":5025,"name":"Break Statement","description":"

When programmers work with loops, they can also use a break expression to stop the loop from executing immediately once the given condition is fulfilled. We can use the break expression with for loop, while loop, and do-while loop.

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Let’s understand how we can use a break expression with each type of loop.

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Break with while loop
\r\n

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We can also use the break expression inside the while loop. If the test condition for the break statement is fulfilled, the nearest enclosing loop breaks.

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Example:

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fun main() {\r\n    var i = 1\r\n    while (i <= 5) {\r\n        println(\"Inside the loop: i = $i\")\r\n        if (i == 3) {\r\n            println(\"Breaking out of the loop\")\r\n            break // This will exit the loop when i equals 3\r\n        }\r\n        i++\r\n    }\r\n    println(\"Outside the loop\")\r\n}

\r\n

Output:

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Inside the loop: i = 1\r\nInside the loop: i = 2\r\nInside the loop: i = 3\r\nBreaking out of the loop\r\nOutside the loop

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Explanation:

\r\n

In this example, a while loop is used to count from 1 to 5. When i reaches 3, the if statement checks if i is equal to 3, and if it is, it executes the break statement. This causes the loop to terminate prematurely.

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\r\n
Break with a do-while loop
\r\n

\r\n

We can use a break expression with a do-while loop, too.

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Example:

\r\n

fun main() {\r\n    var i = 1\r\n    do {\r\n        println(\"Inside the loop: i = $i\")\r\n        if (i == 3) {\r\n            println(\"Breaking out of the loop\")\r\n            break // This will exit the loop when i equals 3\r\n        }\r\n        i++\r\n    } while (i <= 5)\r\n    println(\"Outside the loop\")\r\n}

\r\n

Output:

\r\n

Inside the loop: i = 1\r\nInside the loop: i = 2\r\nInside the loop: i = 3\r\nBreaking out of the loop\r\nOutside the loop

\r\n

Explanation:

\r\n

In this example, a do-while loop is used with similar logic as the previous example. The loop is executed at least once before checking the condition. When i reaches 3, the break statement is executed, causing the loop to terminate prematurely.

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Syntax of while Loop in Kotlin

Initialization:

Condition Check:

Loop Body Execution:

Condition Update:

Condition Recheck:

Repeat:

Output:

Syntax of the do-while loop

Output:

Break with while loop

Example:

Output:

Explanation:

Break with a do-while loop

Example:

Output:

Explanation:

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