4.1 while Loops

• Steps involved in the execution of a `while` loop

  1️⃣ The condition is evaluated.

  2️⃣ If the condition is true, the code block is executed.

  3️⃣ This repeats until the condition becomes false.
• Match the loop type with its characteristic:

  `while` loop ↔️ Unknown number of iterations

  `for` loop ↔️ Fixed number of iterations
• The condition in a `while` loop is evaluated before each iteration to determine whether the loop should continue or terminate
• A `while` loop repeatedly executes a block of code as long as a given condition is true
• How is the loop condition variable updated in the example that prints numbers 1 to 5?

  `i++`
• Match the loop type with its characteristic:

  `while` Loops ↔️ Unknown number of iterations

  `for` Loops ↔️ Fixed number of iterations

  Condition is checked before each iteration ↔️ `while` Loops
• Incrementing or decrementing a variable within a `while` loop is optional.

  False
• What is the initial value of the loop condition variable in the descending loop example?

  5
• Decrementing is used for creating descending loops.
• A `while` loop executes a block of code as long as a given condition is true.
• What is the syntax of a `while` loop in Java?

  while (condition) { }
• What type of expression is the condition in a `while` loop?

  Boolean
• Within a `while` loop, it is common to increment or decrement a variable to control the loop's execution
• Forgetting to update the loop condition variable can lead to an infinite loop.
• What happens if the loop condition variable is not updated in a `while` loop?

  Infinite loop
• Decrementing the loop condition variable is used for descending loops.
• Steps to fix an infinite loop in a `while` loop

  1️⃣ Identify the loop condition variable

  2️⃣ Determine if incrementing or decrementing is needed

  3️⃣ Update the condition variable inside the loop

  4️⃣ Test the loop to ensure it terminates
• The example for incrementing the condition variable is `i++`, while for decrementing it is i--.
• In the input validation example, the loop continues until the user enters a valid integer.
• Steps to iterate through an array using a `while` loop

  1️⃣ Initialize an index variable

  2️⃣ Set the loop condition to check array bounds

  3️⃣ Access array elements using the index

  4️⃣ Increment the index inside the loop
• A `while` loop is a control structure that repeatedly executes a block of code as long as a given condition is true
• The condition in a `while` loop is evaluated after each iteration.

  False
• What is the general syntax of a `while` loop in Java?

  `while (condition) { // code block }`
• What is the initial value of `i` in the example that prints numbers 1 to 5?

  1
• `while` loops require a fixed number of iterations.

  False
• `while` loops are used when the exact number of iterations is unknown.


  True
• The loop terminates when the condition in a `while` loop becomes false
• Forgetting to update the loop condition variable can lead to an infinite loop.
• Match the loop type with its characteristic:

  Incrementing ↔️ Increases the loop condition variable

  Decrementing ↔️ Decreases the loop condition variable
• What boolean expression is used as the condition in the descending loop example?

  i >= 1
• The output of the ascending loop example is the numbers 1 to 5.


  True
• The condition in a `while` loop is checked before each iteration.
• To create a descending loop in a `while` loop, you must decrement the loop condition variable.
• What type of loop is created when the loop condition variable is decremented within a `while` loop?

  Descending
• To fix an infinite loop, you must increment or decrement the loop condition variable.
• Incrementing the loop condition variable is used for ascending loops.
• In the example loop, the condition `i <= 5` will always be true because `i` is never incremented.
• The condition for a descending loop is typically `i >= 1`.


  True
• Match the use of `while` loops with its description:

  Input Validation ↔️ Continuously prompt for valid input

  Counting ↔️ Increment a counter to perform a task

  Processing Collections ↔️ Iterate through elements in an array
• In the counting example, the loop condition is `count < 5`.


  True