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6.1 - Could you repeat that v1?

while loops

The while loop loops through a block of code as long as a specified condition is true.

while (condition) {
  // code block to be executed
}

// This loop will run, over and over again, as long as the variable i
//  is less than 10:
while (i < 10) {
  text += "The number is " + i;
  i++;
}
// Output:
// The number is 0
// The number is 1
// The number is 2
// The number is 3
// The number is 4
// The number is 5
// The number is 6
// The number is 7
// The number is 8
// The number is 9

// This loop counts down the days until winter. It runs as long as 
// daysUntilWinter is greater than 0:
let daysUntilWinter = 5;
while (daysUntilWinter > 0) {
  console.log("Days until Winter: " + daysUntilWinter);
  daysUntilWinter--; // Decrease the counter by 1
}
console.log("It's Winter!");
// Output:
// Days until Winter: 5
// Days until Winter: 4
// Days until Winter: 3
// Days until Winter: 2
// Days until Winter: 1
// It's Winter!

infinite loop

If you forget to update the variable in the loop condition, the loop might never end (infinite loop). It can make your program freeze or hang because it keeps running forever.

your turn: while loop task

Follow these steps to complete the task:

  1. Create a variable called start and set it to any positive number.
  2. Create a variable called count and set it to 0.
  3. Create a while loop that runs while start is greater than 0.
  4. Inside the loop:
    • Subtract 1 from start
    • Add 1 to count
    • Print the value of count
  5. After the loop finishes, print Loop finished!

your turn: while loop task 2

  1. Create a variable steps and set it to 0.
  2. Create a variable n and set it to any positive number.
  3. Create a while loop that runs while n is not equal to 1.
  4. Inside the loop:
    • If n is even, then set n = n / 2.
    • Else, set n = n * 3 + 1.
    • Increase steps by 1
  5. After the loop finishes, print the value of steps.