Contents
Do while loops are a type of loop that runs a set of statements until a condition is met. In this article, we’ll take a look at how do while loops work and how you can use them in your JavaScript programs.
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Introduction
A do-while loop is a control flow statement that allows code to be executed repeatedly based on a given condition. The code inside the do-while loop will always be executed at least once, even if the condition is false, because the condition is only checked after the code inside the loop has been executed.
What is a Do While Loop?
In JavaScript, a do…while loop is a control flow statement that executes a block of code at least once, and then repeats the execution of the code block while a condition evaluates to true. The condition is checked after the code block has been executed.
The syntax for a do…while loop is:
do {
// Statements to be executed
}
while (expression); // Expression must return true or false value
The following example loops through numbers 0-5, displaying each number and its square root. The do…while loop will execute the code block once before checking if the specified condition evaluates to true or false—in this case, it checks if the value of i is less than 5:
The Syntax of a Do While Loop
A do while loop is a control flow statement that allows code to be executed repeatedly based on a given condition. The code inside the do while loop will always be executed at least once, even if the condition is false, because the condition is only checked after the code inside the loop has been executed.
The syntax of a do while loop is:
do {
// code to be executed
} while (condition);
The code inside the do {} block will be executed first, and then the condition will be checked. If the condition evaluates to true, the code inside the do {} block will be executed again. This process will continue until the condition evaluates to false, at which point the execution of the do while loop will stop.
It is important to note that because the condition is only checked after the code in the do {} block has been executed, it is possible for the code inside the do {} block to never be executed if the condition is false from the start.
How Does a Do While Loop Work?
A do while loop is a control flow statement that allows code to be executed repeatedly based on a given condition. The do while loop will always execute the code block at least once, even if the condition is false, because it checks the condition after executing the code block.
When to Use a Do While Loop
A do while loop is a control flow statement that allows us to run a piece of code multiple times. The do while loop is unique because it will always run the code block at least once before checking the condition. A while loop checks the condition before running the code, so it might not run at all.
The syntax for a do while loop is:
do {
//code block to be executed
}
while (condition);
The code block will execute until the condition evaluates to false. Usually, the condition is a comparison between a counter variable and number of times we want to execute the loop. For example, we could use a do while loop to print out each item in an array:
array = [1,2,3,4];
counter = 0;
do {
console.log(array[counter]); //1,2,3,4
counter++; //increment counter by 1 each time we run the loop
} //stop when counter is equal to 4 (the length of our array)
while (counter < array.length);
Conclusion
In conclusion, a do-while loop is a control flow statement that allows code to be executed at least once before checking a condition. The main difference between a do-while loop and a while loop is that a do-while loop is executed at least once before checking the condition while a while loop checks the condition before executing the code.
