JavaScript Variables and Data Types Worksheet

Question 1

Find a reference that lists all the keywords in the JavaScript programming language.

Put a hyperlink here, that links to the keyword reference.
Question 2

True or false: keywords and variable names are NOT case sensitive.

True
Question 3

There are some rules for how you can name variables in JavaScript. What are they?

The first character must start with a letter, underscore, or dollar sign. It can also have no spaces and avoid reserved keywords.
Question 4

What is 'camelCase'?

It's used for variable and function names.
Question 5

What are ALL the different data types in JavaScript (note that there are some that we did not discuss in class)?

Null, Undefined, Boolean, Number, BigInt, String, and Symbol.
Question 6

What is a boolean data type?

It's either a true or false.
Question 7

What happens if you forget to put quotes around a string when you initialize a variable to a string value? How does JavaScript try to interpret this?
For example: var lastName = Jones;

It would be an variable instead of a string and lastName will equal to Jones. JavaScript will interpret it as it's is undefined.
Question 8

What character is used to end a statement in JavaScript?

Replace this text with the solution to the above question/problem.
Question 9

If you declare a variable, but do not initialize it, what value will the variable store?

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Question 10

What output will the following program produce? In other words, explain what you would see in the console log if you ran a program like this:


const firstTestScore = 98;
const secondTestScore = "88";
const sum = firstTestScore + secondTestScore;
console.log(sum);
console.log(typeof sum);
Replace this text with the solution to the above question/problem.
Question 11

What output will the following program produce? In other words, explain what you would see in the console log if you ran a program like this:


const total = 99;
console.log("total");
console.log(total);
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Question 12

What is the difference between these two variables?


const score1 = 75;
const score2 = "75";
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Question 13

Explain why the this code will cause the program to crash:


const score = 0;
score = prompt("Enter a score");
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Coding Problems

Coding Problems - See the 'script' element below this h1 element. You will have to write some JavaScript code in it.

Here are some tips to help you with the coding problems: