Are you ready?

1 questions to solve.

Instructions
  1. This quiz goes to full-screen once you press the Start button, or any Next button after exiting the quiz window.
  2. At the end of the quiz, you are able to review all the questions that you answered wrong and see their explanations.
A statement and expression is the same thing in JavaScript. True or false?
Indeed, statements and expressions are two different concepts in JavaScript. For more details, refer to JavaScript Basics.
All expressions are statements but not all statements are expressions. True or false?
All expressions in JavaScript could also be termed as expression statement, and are therefore statements. But the same does not hold for statements. All statements are not expressions. For more details, refer to JavaScript Basics.
Which of the following definitions best fits with the idea of an expression?
An expression is a piece of code that resolves down — or in other words, evaluates — to a given value. This goes with choice (B). For more details, refer to JavaScript Basics — Expressions.
Is 5 + 5 an expression or a statement?
5 + 5 is an expression, and since all expressions are also statements, it is a statement as well. This goes with choice (C). For more details, refer to JavaScript Basics.
Which of the following denotes a primary expression?
Numbers and strings, in their literal forms, denote primary expressions. Hence the correct answer for this question is (D). For more details, refer to JavaScript Basics — Expressions.
null is a primary expression in JavaScript. True or false?
Indeed, null is a primary expression, as it doesn't contain any other expression in itself. Hence, the correct choice is (A). For more details, refer to JavaScript Basics — Primary Expressions.
What would the following code log?
console.log(50 != 5);
!= is the not-equal operator. It returns true when the given values are not equal to one another. In this case, since 50 is not equal to 5, we get true returned, and consequently logged. For more details, refer to JavaScript Basics — Relational Expressions.
What would the following code log?
console.log(10 == 10);
== is the equal operator. It returns true when the given values are equal to one another, and false otherwise. In this case, since 10 is indeed equal to 10, we get true returned, and consequently logged. For more details, refer to JavaScript Basics — Relational Expressions.
How to declare a variable in JavaScript?
The var keyword is used to declare variables in JavaScript. Hence, the correct choice is (C). For more details, refer to JavaScript Basics — Variables.
What does the following code log?
var x = 10;
console.log(x + 10);
In this code, x holds the number 10, hence x + 10 literally translates to 10 + 10 which gives 20. The correct choice is therefore (A). For more details, refer to JavaScript Basics — Variables.
Which of the following definitions best describes a string?
A string is a sequence of textual characters. This goes with choice (D). For more details, refer to JavaScript Basics — Strings.
Which of the following values denotes a string?
In JavaScript, a string could be denoted using single quotes ('') or double quotes (""). Hence, both 'Hello' and "Hello" are strings. The correct choice is therefore (C). For more details, refer to JavaScript Basics — Strings.
Which of the following denotes the three functions in JavaScript that display dialog boxes?
The functions alert(), confirm() and prompt() display dialog boxes. Hence, the correct choice is (A). For more details, refer to JavaScript Basics — Dialog boxes.
What does the following code log?
console.log(Number('10'));
Passing a string to the Number() function returns back the equivalent number. In this case, we get back the number 10, which consequently gets logged in the console. The correct choice is therefore (B). For more details, refer to JavaScript Basics — Conversion to number.