JavaScript Fundamentals

What is the value of “a” in the following statement?

var a;

• undefined

• null

• 0

• NaN

What is the value of:

”41” + 1

• 42

• “42”

• 411

• “411”

What is the value of:

”31” - 1

• “30”

• 30

• “311”

• NaN

What is the extension for a JavaScript file?

• .java

• .jar

• .js

• .sj

JavaScript functions can access variables defined in the same scope?

• True

• False

Variables defined inside of functions are accessible outside of the function?

• True

• False

What is the name of the JavaScript standard?

• JavaScript

• ECMA Script

• JS

• PEP

In JavaScript strings must be defined using only double quotes (“).

• True

• False

Which list contains the correct data types in JavaScript?

• numbers, strings, booleans, symbols, objects, null, and undefined

• numbers, strings, booleans, symbols, objects, Nan, and undefined

• numbers, strings, booleans, symbols, objects, null, and undefined

• numbers, strings, booleans, symbols, objects, null

Which of the following statements are correct?

• The `let` keyword will throw an error if you try to declare the same variable a second time.

• The `const` keyword, will not allow you to redeclare and reassign the variable

• The `var` keyword declares variables that are processed before any code is executed

• None of the above