Computing 3.13-3.17

Why do we use while loops in JavaScript?

• To break out of some block of code

• To do something if a condition is true

• To repeat some code while a condition is true

• To repeat something for a fixed number of times

Which general while loop definition is written correctly?

• while (x is true) {

  // code

  }

• if (i<5) {

  //code

  }

• while (var i = 0; i < count; i++) {

  //code

  }

• while (condition) {

  //code

  }

What do we use control structures for in JavaScript?

• Control the flow of the program; how the commands execute

• Start our JavaScript program

• Store information for later

• Teach Karel new commands

Which of the below are examples of control structures?

1 - if

2 - if/else

3 - while

4 - for

• 1 only

• 1 and 2 only

• 3 and 1 only

• 1, 2, 3, and 4

You need to write a program that has Karel move 6 times and then put a ball. Which control structure do you use?

• For loop

• While Loop

• If Statement

• If/Else Statement

• None of these

You need to write a program that has Karel take all the tennis balls where Karel is standing if there are any there.

Karel should end up with no tennis balls on that spot.

What control structure do you need to use?

• For Loop

• While Loop

• If Statement

• If/Else Statement

• None of these

You need to write a program that has Karel put down a tennis ball if the world has dimensions of 1x1.

What control structure do you use?

• For Loop

• While Loop

• If Statement

• If/Else Statement

• None of these

You need to write a program that has Karel move if the front is clear, but if it isn’t clear, Karel will do nothing.

Which control structure do you need to use?

• For Loop

• While Loop

• If Statement

• If/Else Statement

• None of these

You need to write a program where Karel will take a ball if there is a ball present, otherwise Karel should put down a ball.

Which control structure do you need to use?

• For Loop

• While Loop

• If Statement

• If/Else Statement

• None of these

Why should a programmer indent their code?

• Helps show the structure of the code

• Easier for other people to understand

• Indenting is a key part of good programming style

• All of the above