Coalition of Information Technology Business

Question 16

Coalition of Information Technology Business. Which JavaScript function is used to convert a string into an integer?

• toInt()
• convertInt()
• parseInt()
• stringToInt()

Question 17

In JavaScript, what does NaN stand for?

• Not a Null
• Not a Number
• Negative and Null
• None and Null

Question 18

Which of the following is the correct JavaScript statement to display text on a webpage?

• response.write(“Hello how are you?”)
• “Hello how are you?”
• document.write(“Hello how are you?”)
• (“Hello how are you?”)

Question 19

What happens if you define a function incorrectly in JavaScript (e.g., missing parentheses or using invalid syntax)?

• ✅ It will result in a syntax error
• The function will continue to execute
• It will result in no syntax errors
• All of the above

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Question 20

Which type of loop is NOT a standard loop structure in JavaScript?

• for loop
• ✅ repeat loop
• while loop
• do…while loop

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Question 21

Which method is used in JavaScript to access an HTML element by its ID?

• Use the document.putElementById(id) method
• ✅ Use the document.getElementById(id) method
• Use the document.retrieveElementById(id) method
• Use the document.accessElementById(id) method

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Question 22

Which of the following is the correct way to link an external JavaScript file in HTML?

• ✅ <script src=”main.js”>
• <script href=”main.js”>
• <script name=”main.js”>
• <script value=”main.js”>

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Question 23

Which of the following is the correct definition of a boolean?

• ✅ A logical data type which makes decisions. It supports only two possible values true or false
• A logical data type which makes functions. It supports only one possible value const boolean = () => {}
• A data type used to store functions, and arrays using scientific notation
• A whole number without a decimal point

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Question 24

Which of the following is the correct when to use floating-point numbers in JavaScript?

• A data type used to store functions, and arrays using scientific notation
• A whole number without a decimal point
• A general data type used to store integers, floating-point numbers (decimals), and numbers using scientific notation
• ✅ Used whenever you’re working with data that requires numbers with a fractional component

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Question 26

Which loop in JavaScript always executes the code block at least once before checking the condition?

• for
• while
• ✅ do…while
• forEach

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Question 27

Which option best describes null in JavaScript?

• ✅ Null refers to something with no value and explicitly set as null with code
• Null refers to something with a value of void and explicitly set as void with code
• Null refers to something with a value of undefined
• Null refers to something with a value of 0

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Question 28

Which is the correct way to declare an object person with properties name and age in JavaScript?

• ✅ let person = { name: “John”, age: 30 };
• let person = (name: “John”, age: 30);
• let person = “name”: “John”, “age”: 30;
• let person = [“name”: “John”, “age”: 30];

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Question 29

Which of the following is NOT a valid way to declare a variable in JavaScript?

• let a = 10;
• var a = 20;
• ✅ int a = 30;
• const a = 40;

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Question 30

Which of the following is the correct definition of BigInt in JavaScript?

• ✅ Type that represents integers that are too large for the standard Number type and has no limit
• Type that has a maximum value of $2^{53} – 1$, which is about 9 quadrillion
• Type that has a maximum value of $5^{06} – 1$, which is about 18 quadrillion
• Type that represents integers that are too small for the standard Number type and has no limit

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Question 31

Which of the following is a valid way to declare a variable and assign it the value of 10 in JavaScript?

• variable x = 10;
• ✅ var x = 10;
• let x := 10;
• declare x = 10;

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Question 34

Which keyword in JavaScript is used to declare a variable whose value cannot be reassigned after initialization?

• var
• let
• ✅ const
• Set

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Question 36

Which expression is the safest way to check if a variable is truly undefined, even if it hasn’t been declared?

• myVar == undefined
• ✅ typeof myVar === ‘undefined’
• myVar === undefined
• isUndefined(myVar)

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Question 37

Which of the following is true about the Object.assign() method in JavaScript?

• It copies the values of all properties from one or more source objects to a target object.
• It merges two or more objects into a new object.
• It creates a shallow copy of an object.
• ✅ All of the above

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Question 38

What does the JavaScript slice() method do when used on an array?

• Removes the last element of an array.
• ✅ Extracts a portion of an array into a new array.
• Splits an array into smaller arrays.
• Combines two arrays into one.

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Question 39

Which of the following is a correct way to add or update a property on a JavaScript object using dot notation?

• object{property} = value
• object.addProperty(“property”, value)
• ✅ object.property = value
• object[“property”] = value

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Question 40

Which of the following is a correct way to list the property names of a JavaScript object?

• Object.values()
• ✅ Object.keys()
• Object.entries()
• Object.getOwnPropertyNames()

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Question 41

Which array method combines all elements of an array into a single string, separated by a specified delimiter?

• ✅ join()
• concat()
• split()
• toString()

Question 42

Which statement correctly describes how to add an element to the end of an array in JavaScript?

• Use the array.pop() method
• ✅ Use the array.push() method
• Use the array.shift() method
• Use the array.unshift() method

Question 47

Which loop is used to iterate over iterable objects (like arrays, strings, maps, etc.) in JavaScript?

• for…of ✅
• for…in
• while
• do…while

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Question 48

Which JavaScript operator is used for string concatenation?

• /
• + ✅

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Question 49

Which data type can be used to group related data and functionality together in JavaScript?

• object ✅
• null
• undefined
• String

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Question 50

Which JavaScript operator is used as the conditional (ternary) operator?

• ===
• ? ✅
• :
• !!

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Question 51

What does the JavaScript method Array.isArray() do?

• Checks if an array is empty.
• Checks if a variable is an array. ✅
• Concatenates two arrays.
• Removes duplicates from an array.

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Question 52

Which HTML tag is used to embed or reference JavaScript code in a web page?

• <javascript>
• <js>
• <script> ✅
• <scripting>

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Question 53

Which ECMAScript version introduced arrow functions like () => {}?

• ECMAScript ES5
• ECMAScript ES8
• ECMAScript ES7
• ECMAScript ES6 ✅

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Question 54

Which of the following is the correct way to define a function named greet in JavaScript?

• function greet(name) { console.log(“Hello ” + name); } ✅
• def greet(name) { console.log(“Hello ” + name); }
• function greet name { console.log(“Hello ” + name); }
• function = greet(name) { console.log(“Hello ” + name); }

Question 59

What happens when you try to access a property that doesn’t exist on a JavaScript object?

• JavaScript throws an error
• It returns undefined
• It returns null
• It creates the property automatically

Question 64

Which JavaScript operator checks for equality without performing type coercion (strict equality)?

• ===
• ==
• =
• !=

Question 65

Which method is used to add one or more elements to the end of an array in JavaScript?

• append()
• ✅ push()
• add()
• attach()

Question 66

Which of the following best describes the general JavaScript Number data type?

• ✅ A general data type used to store integers, floating-point numbers (decimals), and numbers using scientific notation
• A whole number without a decimal point
• Used whenever you’re working with data that requires numbers with a fractional component
• A data type used to store functions, and arrays using scientific notation

Question 67

Which array method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value? Coalition of Information Technology Business

• ✅ reduce()
• forEach()
• map()
• filter()

Question 68

What does the JavaScript function parseFloat() do?

• Parses a string and returns an integer.
• Rounds a number to the nearest integer.
• Converts a number to a string.
• ✅ Parses a string and returns a floating-point number.

Question 75

Which statement correctly describes block-scoped variables in JavaScript?

• [✔] Block-scoped variables are only accessible inside the block in which they are defined.
• Block-scoped variables are accessible anywhere in the function.
• Block-scoped variables are accessible anywhere in the entire program.
• Block-scoped variables are inaccessible once the block is finished.

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Question 76

Which of the following is the correct syntax for accessing the value of a property in a JavaScript object using bracket notation?

• object{key}
• object.key
• [✔] object[“key”]
• object.key()

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Question 77

Which of the following is the most common and straightforward way to declare an array with numbers 1, 2, and 3 in JavaScript?

• [✔] let arr = [1, 2, 3];
• let arr = new Array(1, 2, 3);
• let arr = Array(1, 2, 3);
• let arr = [1, “2”, 3];

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Question 78

Which JavaScript array method removes the last element from an array?

• removeLast()
• deleteLast()
• [✔] pop()
• splice()

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Question 79

Which operator in JavaScript checks if two values are NOT equal both in value and type?

• !=
• [✔] !==
• ==
• ===

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Question 80

Which of the following statement is correct?

• JavaScript is a High-Level Procedulary-Oriented, Multi-Paradigm Programming Language
• JavaScript is a Low-Level Procedulary-Oriented, Single-Paradigm Programming Language
• [✔] JavaScript is a High-Level Object-Oriented, Multi-Paradigm Programming Language
• JavaScript is a Low-Level Object-Oriented, Multi-Paradigm Programming Language

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Question 81

Which of the following are valid ways to access the age property of a JavaScript object named person?

• person.get(‘age’)
• [✔] person.age
• person.getProperty(‘age’)
• person[age]

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Question 82

Which of the following is the single-line comment symbol in JavaScript?

• [✔] //
• /* */

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Question 83

Which array method is used to merge two or more arrays without modifying the original arrays?

• [✔] concat()
• join()
• slice()
• push()

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Question 84

Which statement correctly explains the difference between parameters and arguments in programming?

• [✔] Parameters are used in the function definition, while arguments are the values that are passed into the function parameters when it is called
• Parameters are values passed to a function, while Arguments are placeholders within the function
• Parameters refer to data types, while Arguments represent the functions name
• Parameters are used for conditional statements, while Arguments are utilized for loops within a function

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Question 86

Which option best describes an integer in programming, specifically in JavaScript?

• A data type used to store functions, and arrays using scientific notation
• Used whenever you’re working with data that requires numbers with a fractional component
• [✔] A whole number without a decimal point
• A general data type used to store integers, floating-point numbers (decimals), and numbers using scientific notation

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Question 87

Which of the following is a primitive data type used to represent a logical truth value in JavaScript?

• [✔] true
• false
• undefined
• null

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Question 88

What does the break statement do inside a loop in JavaScript?

• [✔] Exits the loop and stops the code inside it from executing.
• Pauses the loop for a specified period of time.
• Skips the current iteration and continues with the next one.
• It causes an error in the loop. Coalition of Information Technology Business