Programming with JavaScript

Module quiz: Introduction to JavaScript 

1. You can run JavaScript in a web browser's devtools console.

• true
• false

2. Which of the following are valid comments in JavaScript? Select all that apply.

• \ Comment 1
• // Comment 2
• ##
  ## Comment 3
  ##
• /*
   * Comment 4
   */

3. Which of the following are valid data types in JavaScript? Select all that apply.

• string
• numbers
• booleans
• null

4. Which of the following is the logical AND operator in JavaScript?

• &
• &&
• ||
• |\

5. Which of the following is the assignment operator in JavaScript?

• =
• ==
• ===

6. How many times will the following code print the word 'Hello'?

  for(var i = 0; i <= 5; i++) {

    console.log("Hello");

  }

• 4
• 5
• 6

7. What will print out when the following code runs?

  var i = 3;

  var j = 5;

  if(i == 3 && j < 5) {

    console.log("Hello");

  } else {

    console.log("Goodbye");

  }

• Hello
• Goodbye
• Nothing

8. What will print out when the following code runs?

  var i = 7;

  var j = 2;

 

  if(i < 7 || j < 5) {

    console.log("Hello");

  } else {

    console.log("Goodbye");

  }

• Hello
• Goodbye
• Nothing

9. The result of !false is:

• true
• undefined

10. What does the operator symbol || represent in JavaScript?

• The logical NOT operator
• The logical OR operator
• The logical AND operator

Module quiz: The Building Blocks of a Program

1. What data type is the variable  x ?

  var x = {};

• Function
• Array
• Object

2. What will be the output of running the following code?  

try {

console.log('hello)

} catch(e) {

console.log('caught')

}

• Uncaught SyntaxError: Invalid or unexpected token.
• Caught

3. What value is printed when the following code runs?

  var burger = ["bun", "beef", "lettuce", "tomato sauce", "onion", "bun"];

  console.log(burger[2]);

• bun
• beef
• lettuce
• tomato sauce
• onion

4. In the following code, how many methods does the  bicycle  object have?

  var bicycle = {

      wheels: 2,

      start: function() {

 

      },

      stop: function() {

 

      }

  };

• 1
• 2
• 3

5. When the following code runs, what will print out?

  try {

    throw new Error();

    console.log('Hello');

  } catch(err) {

    console.log('Goodbye');

  }

• Hello
• Goodbye

6. If you mis type some code in your JavaScript, what kind of error will that result in?

• RangeError
• SyntaxErrror
• TypeError

7. Will the following code execute without an error?

  function add(a, b) {

    console.log(a + b)

  }

  add(3, "4");

• Yes
• No

8. What will be printed when the following code runs?

  var result;

  console.log(result);

• undefined
• null
• 0

9. What will be the output of the following code?

var str = "Hello";

str.match("jello");

• null
• undefined
• empty string

10. What will be the output of the following code?

try {

Number(5).toPrecision(300)

} catch(e) {

console.log("There was an error")

}

• RangeError
• 5
• e
• "There was an error"

Module quiz: Programming Paradigms

1. Variables declared using  'let' can be reassigned.

• true
• false

2. What will print out when the following code runs?

    function scopeTest() {

        var y = 44;

        console.log(x);

    }

    var x = 33;

    scopeTest();

• null
• undefined
• 33
• 44

3. What will print out when the following code runs?

    class Cake {

        constructor(lyr) {

            this.layers = lyr;

        }

        getLayers() {

            return this.layers;

        }

    }

    class WeddingCake extends Cake {

        constructor() {

            super(2);

        }

        getLayers() {

            return super.getLayers() * 5;

        }

    }

    var result = new WeddingCake();

    console.log(result.getLayers());

• 0
• 2
• 5
• 10

4. What will print out when the following code runs?

    class Animal {

 

    }

 

    class Dog extends Animal {

        constructor() {

            super();

            this.noise = "bark";

        }

 

        makeNoise() {

          return this.noise;

        }

    }

 

    class Wolf extends Dog {

        constructor() {

            super();

            this.noise = "growl";

        }

    }

 

    var result = new Wolf();

    console.log(result.makeNoise());

• bark
• growl
• undefined

5. Consider this code snippet: 'const  [a, b]  =  [1,2,3,4] '. What is the value of  b?

• undefined
• 1
• 2
• [1,2,3,4]

6. What value will be printed out when the following code runs?

    function count(...food) {

        console.log(food.length)

    }

    count("Burgers", "Fries", null);

• 2
• 3
• "Burgers", "Fries", null
• "Burgers", "Fries", undefined

7. Which of the following are JavaScript methods for querying the Document Object Model? Select all that apply.

• getElementsByClassName
• getElementsById
• getElementById
• getElementByClassName
• queryAllSelectors
• querySelector

8. Which of the following methods convert a JavaScript object to and from a JSON string?

• JSON.parse
• JSON.stringify
• JSON.fromString
• JSON.toString

9. What will be the result of running this code?  

const letter = "a"

letter = "b"

• Uncaught TypeError: Assignment to constant variable   
• b
• a
• Uncaught SyntaxError: Invalid or unexpected token

10. What is a constructor?

• A function that is called to create an instance of an object.  
• An instance of a class.
• A specific object that has been created using the class name.
• An object literal  

Module quiz: Testing

1. Which of the following is a framework that can help you run a unit test?

• JFrame
• Jest
• JavaTest
• JavaFrame

2. When the following test executes, what will the test result be?

function subtract(a, b) { 

      return a   b; 

     } 

 expect(subtract(10, 4)).toBe(6); 

• Success.
• Fail.

3. True or False: End to end testing is the slowest and most expensive type of testing.

• True.
• False

4. What reason would you want to know about your code coverage?

• It lets you know where more testing may be required.
• It lets you know if you are done writing code.
• It lets you know if you are testing correctly.
• It lets you know if your code is in Javascript.

5. The development of Node.js led to the ability to do which of the following?

• Run unit tests
• Estimate code coverage
• Download and manage packages
• Write full stack JavaScript programs.

6. Which of the following are NOT one of the three types of testing?

• Integration testing
• End to end testing
• Post hoc testing
• Unit testing

7. True or False: You can install packages from the npm repository using the node command.

• True
• False

8. Which file lists all your application's required node packages?

• node.json
• pkg.json
• npm.json
• package.json

9. Which of the following statements are NOT benefits of using Test Driven Development or TDD?

• Minimizing regressions like accidental bugs introduced to old code.
• You have proof that your new implementation is not breaking other parts of the app.
• You can automate these tests easily and thus keep verifying again and again that the system works as expected.
• You can run tests without setting them up.

10. Which of the below statements would NOT be a benefit of Mocking?

• You can test the front end functionality of your web app by mocking the data as if it came back from a server.
• Mocks, allow you to pretend that users are already there if the backend hasn't been built yet.
• Mocking is a substitute for testing.
• Mocking allows you to separate the code that you are testing from its related dependencies.