Working with JavaScript

Question 1

What is Debugging?

Answer 1

Debugging is the process of identifying and fixing errors in a code.

Question 2

What is Logging?

Answer 2

Logging is a way to check code as it’s being developed.

Question 3

What does Logging look like?

Answer 3

Logging looks like the printing of values to a display as the code runs.

Question 4

What is the Console?

Answer 4

The Console is a tool which displays feedback like logs, and errors when things go wrong.

Question 5

What do you write in JavaScript to ‘print’ something to the Console?

Answer 5

In JavaScript, you write console.log() to ‘print’ something to the Console.

Question 6

What does console.log() let you see?

Answer 6

console.log() lets you see the output when the code is ran.

Question 7

What will console.log(‘hello’) print to the console?

Answer 7

hello

Question 8

What will console.log(4) print to the console?

Answer 8

4

Question 9

What will console.log(4+10) print to the console?

Answer 9

14

Question 10

Can Debugging check the data types of Variables?

Answer 10

Yes, Debugging can check the data types of variables.

Question 11

What does the typeof operator do?

Answer 11

the typeof operator can tell you what kind of data type any kind of value is.

Question 12

Can the typeof operator tell you what kind of data type values stored within variables are?

Answer 12

Yes

Question 13

How do you see the data type printed to the console?

Answer 13

Combine the typeof operator with the console.log() to see the data type printed to the console.

Question 14

What type will print to the console?

console.log(typeof ‘hello’);

Answer 14

the console will print the type ‘string’

Question 15

What type will print to the console?

console.log(typeof 4);

Answer 15

the console will print the type ‘number’

Question 16

What type will print to the console?

console.log(typeof(9+5));

Answer 16

the console will print the type ‘number’

Question 17

Why is there an extra bracket?

console.log(typeof(9+5));

Answer 17

There is an extra bracket because the expression needs to evaluate itself first before it can identify the final data type.

Question 18

What type will print to the console?

console.log(typeof name);

Answer 18

The console will print the type ‘string’

Question 19

What are Comments?

Answer 19

Comments in JavaScript are text within code that are ignored by the JavaScript Coding Engine when running the code.

Question 20

What are Comments used as a Tool for?

Answer 20

Comments are used as a tool for Planning and for communication with other developers. It’s good for trying to recall the reason behind doing something the way you did.

Question 21

What is the syntax for Single-Line Comments?

Answer 21

// is the syntax for single line comments

Question 22

What is the syntax for Double-Line Comments?

Answer 22

/* is the syntax for multi line comments

Question 23

Is the syntax for Double-line comments reversed at the end?

Answer 23

Yes.

Question 24

What is Pseudocode?

Answer 24

Pseudocode is the common term given to code that expresses a sequence of code in human language.

Question 25

What is one way to achieve pseudocode?

Answer 25

comments are one way of achieving pseudocode.

Question 26

What is an Error Message?

Answer 26

An Error Message is a type of feedback that occurs when something goes wrong. They assist with debugging code.

Question 27

What is an example of a syntax error?

Answer 27

const food = 'cheese" is an example of a syntax error

Question 28

When does a reference error occur?

Answer 28

A reference error occurs when a code attempts to use a variable that isn't available or hasn't been declared before the time we use it.

Question 29

Why would this code cause an error? console.log(food); const food='cheese';

Answer 29

It would cause an error because the variable has been logged before it has been declared.

Question 30

When does a Type Error Occur?

Answer 30

A Type Error will Occur when we attempt to use a data type in a way that isn't permitted.