Computer Science While Loops

What is the sentinel value in this ? int num = 0, sum = 0; while(num != -1) { System.out.println("Enter a positive " +"integer (-1 to quit)"); num = scan.nextInt(); if(num != -1) sum += num; } System.out.println(sum);

-1

What is the minimum number of times that ANY while loop will repeat?

0

What will this code display? int i = 0; while (i < 5) { System.out.print (i + ", "); i ++; }

0, 1, 2, 3, 4,

What will this code display? int i = 0; do { System.out.print (i + ", "); } while (i < 5);

0, repeated forever

How many times does this run? int i = 9; do { System.out.print(i + " "); i++; } while(i<=5);

1

How many times will the following code print "Welcome to Java"?int count = 0;do { System.out.println("Welcome to Java"); count++;} while (count < 10);

10

How many times will the following code print "Welcome to Java"?int count = 0;while (count < 10) { System.out.println("Welcome to Java"); count++;}

10

What is the first number printed? Int value = 15; while (value < 28) { System.out.println(value); value++; }

15

What is the value equal to after the loop ends? Int value = 15; while (value < 28) { System.out.println(value); value++; }

28

What is the output of the following code?int x = 0;while (x < 4) { x = x + 1;}System.out.println("x is " + x);

4

What is wrong with the code below? int i = 0; While (i < 5) { System.out.println(i); i++; }

The While is incorrectly capitalized

What is wrong with the code below? int i = 0; while (i < 5) { System.out.println(i); } i++;

The closing curly bracket is in the wrong place , the counter value never increases, the loop never ends

What is a sentinel value?

a value to be typed in to stop a loop

what does ++ mean ?

adds one to a variable

where does the while statement go in a do-loop?

after and outside the do loop

Which loop will execute the body of loop even when condition controlling the loop is initially false?

do while loop

When a piece of code runs unintentionally forever it is known as

infinite loop

The difference between a while loop and a do while loop is

it is possible for a while loop to not run at all

what happens if the condition is initially false?

it never runs

Is this correct? while (condition);

no, has the semi colon

How many times do do-loops run at least

once

what does -- mean?

subtracts one from a variable

when does the while loop stop?

when the condition is false

What's the output int x = 0, y = 0; y = x++ + 1; System.out.println("x=" +x + ", y=" + y);

x = 1 y= 1

What's the output ? int x = 0, y = 0; y = ++x + 1; System.out.println("x=" +x + ", y=" + y);

x = 1 y=2

In a do-loop, do you need a semi colon after the while statement?

yes

does a while loop need curly braces?

yes

is this: count = count + 1 the same as count += 1 ?

yes