JavaScript Fundamentals Quiz

Test your understanding of JavaScript concepts

Question 1 of 20

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JavaScript in HTML

In what order will these console.log messages appear?

<html>
<head>
    <script>console.log("Script A");</script>
</head>
<body>
    <h1>My Website</h1>
    <script>console.log("Script B");</script>
    <p>Content here</p>
    <script>console.log("Script C");</script>
</body>
</html>
                

Script B, Script A, Script C Script A, Script B, Script C Script C, Script B, Script A They all run simultaneously

JavaScript in HTML

Which JavaScript inclusion method is best for a large project with multiple pages?

Inline JavaScript (onclick="...") Internal JavaScript (<script> tags) External JavaScript (.js file) All methods are equally good

Variables

Complete the variable declaration for a constant school name:

Declare a constant variable named "schoolName" with the value "JavaScript Academy":

Data Types

What is the data type of: [1, 2, 3, 4]?

String Number Array Object

Variables

Predict the output:

let firstName = "Alice";
let lastName = "Johnson";
console.log(firstName + " " + lastName);
                

Functions

What will this function return when called with calculateGrade(85)?

function calculateGrade(score) {
    if (score >= 90) {
        return "A";
    } else if (score >= 80) {
        return "B";
    } else {
        return "C";
    }
}
                

"A" "B" "C" undefined

Functions

Write a function declaration that takes two numbers and returns their sum:

Control Structures

What will this code output?

let temperature = 25;
if (temperature > 30) {
    console.log("Hot");
} else if (temperature > 20) {
    console.log("Warm");
} else {
    console.log("Cold");
}
                

"Hot" "Warm" "Cold" Nothing

Loops

How many times will this loop run?

for (let i = 0; i < 4; i++) {
    console.log("Count: " + i);
}
                

3 times 4 times 5 times Infinite times

Arrays

What will be the result after these operations?

let fruits = ["apple", "banana"];
fruits.push("orange");
console.log(fruits);
                

["apple", "banana"] ["apple", "banana", "orange"] ["orange", "apple", "banana"] Error

Arrays

What is colors[2] for this array?

let colors = ["red", "blue", "green", "yellow"];

Objects

Create an object to represent a book with title "JavaScript Guide":

Objects

How do you access the student's name from this object?

let student = {
    name: "Sarah",
    age: 22,
    courses: ["Math", "Science"]
};
                

student.name student[name] student->name student.getName()

DOM

How do you select an element with id "main"?

document.getElementById("main") document.getElement("main") document.querySelector("main") document.select("#main")

Events

What event fires when a user clicks on an element?

"press" "click" "tap" "select"

Debugging

What's wrong with this code?

let name = "Alice"
let age = 25

if age > 18 {
    console.log(name + " is an adult");
}
                

Missing semicolons and parentheses in if statement Variables should use var instead of let The condition should use = instead of > Nothing is wrong

Code Reading

What will be the final value of x?

let x = 5;
let y = 10;

if (x < y) {
    x = x + 2;
}

console.log("x is now: " + x);
                

Arrays

Which method removes the last element from an array?

push() pop() shift() unshift()

Functions

Convert this function to an arrow function:

function multiply(a, b) {
    return a * b;
}
                

Integration

Which is the best practice for including JavaScript in HTML?

Put all scripts in the <head> section Use only inline JavaScript for everything Place scripts at the end of <body> or use defer attribute JavaScript should never be used with HTML

Quiz Complete! 🎉

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