1.
What is the object type?
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Xamarin JavaScript interview questions.
Only challenges
- 2.
Explain arrays in JavaScript
Answer:
- 3.
What is typeof operator?
Answer:
- 4.
Explain equality in JavaScript
Answer:
- 5.
What is Scope in JavaScript?
Answer:
- 6.
Explain Values and Types in JavaScript
Answer:
- 7.
What is let keyword in JavaScript?
Answer:
- 8.
Explain the same-origin policy with regards to JavaScript.
Answer:
- 9.
What is the difference between == and ===?
Answer:
- 10.
Is there anyway to force using strict mode in Node.js?
Answer:
- 11.
Why would you use something like the load event? Does this event have disadvantages? Do you know any alternatives, and why would you use those?
Answer:
- 12.
What is strict mode?
Answer:
- 13.
What's the difference between Host objects and Native objects?
Answer:
- 14.
What language constructions do you use for iterating over object properties and array items?
Answer:
- 15.
What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?
Answer:
- 16.
Explain event bubbling and how one may prevent it
Answer:
- 17.
What does use strict do?
Answer:
- 18.
Why is it, in general, a good idea to leave the global scope of a website as-is and never touch it?
Answer:
- 19.
What is a Polyfill?
Answer:
- 20.
Explain Null and Undefined in JavaScript
Answer:
- 21.
What's the difference between throw Error('msg') vs throw new Error('msg')?
Answer:
- 22.
Lucky sevens
Answer:
- 23.
Simple clock angle
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- 24.
Sum of several arrays
Answer:
- 25.
Test divisors of three
Answer:
- 26.
Oddball sum
Answer:
- 27.
Sum of Array Plus One
Answer:
- 28.
String Rotation
Answer:
- 29.
Make this work
Answer:
- 30.
Given a string, reverse each word in the sentence
Answer:
- 31.
Implement enqueue and dequeue using only two stacks
Answer:
- 32.
Write a "mul" function which will properly when invoked as below syntax
Answer:
- 33.
Explain what a callback function is and provide a simple example
Answer:
- 34.
How to empty an array in JavaScript?
Answer:
- 35.
Find the missing number in O(n) time
Answer:
- 36.
Write a function that would allow you to do this?
Answer:
- 37.
Remove duplicates of an array and return an array of only unique elements
Answer:
- 38.
How to check if an object is an array or not? Provide some code.
Answer:
- 39.
How would you check if a number is an integer?
Answer:
- 40.
Two sum problem
Answer:
- 41.
Determine overlapping numbers in ranges
Answer:
- 42.
Stock maximum profit
Answer:
- 43.
Tree Level Order Print
Answer:
- 44.
Step-by-step solution for step counting using recursion
Answer:
- 45.
Implement Bubble Sort
Answer:
- 46.
What is IIFEs (Immediately Invoked Function Expressions)?
Answer:
- 47.
What is Coercion in JavaScript?
Answer:
- 48.
What is the difference between a shim and a polyfill?
Answer:
- 49.
What is the definition of a Higher-Order Function?
Answer:
- 50.
What do you think of AMD vs CommonJS?
Answer:
- 51.
Explain the differences on the usage of foo between function foo() {} and var foo = function() {}
Answer:
- 52.
What is the drawback of creating true private in JavaScript?
Answer:
- 53.
What's the difference between .call and .apply?
Answer:
- 54.
What is the preferred syntax for defining enums in JavaScript?
Answer:
- 55.
Describe Closure concept in JavaScript as best as you could
Answer:
- 56.
Could you explain the difference between ES5 and ES6
Answer:
- 57.
When should we use generators in ES6?
Answer:
- 58.
Explain Function.prototype.bind.
Answer:
- 59.
What are the benefits of using spread syntax in ES6 and how is it different from rest syntax?
Answer:
- 60.
When should I use Arrow Functions in ES6?
Answer:
- 61.
Explain the difference between undefined and not defined in JavaScript
Answer:
- 62.
What are the advantages and disadvantages of using use strict?
Answer:
- 63.
What is Currying?
Answer:
- 64.
What are the differences between ES6 class and ES5 function constructors?
Answer:
- 65.
Why should we use ES6 classes?
Answer:
- 66.
Explain the difference between Object.freeze() vs const
Answer:
- 67.
How to compare two objects in JavaScript?
Answer:
- 68.
What will be the output of the following code?
Answer:
- 69.
What is a closure, and how/why would you use one?
Answer:
- 70.
What will be the output of the following code?
Answer:
- 71.
What's a typical use case for anonymous functions?
Answer:
- 72.
Suggest one simple way of removing duplicates from an array using ES6
Answer:
- 73.
What is generator in JS?
Answer:
- 74.
What is the difference between document load event and document DOMContentLoaded event?
Answer:
- 75.
What's the difference between using let and var to declare a variable in ES6?
Answer:
- 76.
What is the motivation for bringing Symbol to ES6?
Answer:
- 77.
Why is extending built-in JavaScript objects not a good idea?
Answer:
- 78.
What is the difference between Anonymous and Named functions?
Answer:
- 79.
Provide some examples of non-bulean value coercion to a boolean one
Answer:
- 80.
Given an array of integers, find the largest difference between two elements such that the element of lesser value must come before the greater element
Answer:
- 81.
What will the following code output?
Answer:
- 82.
Write a function that would allow you to do this
Answer:
- 83.
Given an array of integers, find the largest product yielded from three of the integers
Answer:
- 84.
What will be the output of the following code?
Answer:
- 85.
Check if a given string is a palindrome. Case sensitivity should be taken into account.
Answer:
- 86.
Find the intersection of two arrays
Answer:
- 87.
Write a recursive function that returns the binary string of a given decimal number
Answer:
- 88.
How would you use a closure to create a private counter?
Answer:
- 89.
FizzBuzz Challenge
Answer:
- 90.
Given two strings, return true if they are anagrams of one another
Answer:
- 91.
All Permutations (Anagrams) of a String
Answer:
- 92.
Find all string combinations consisting only of 0, 1 and ?
Answer:
- 93.
Generate all balanced bracket combinations
Answer:
- 94.
Implement a queue using two stacks
Answer:
- 95.
Throttle Function Implementation
Answer:
- 96.
Find Word Positions in Text
Answer:
- 97.
Merge two sorted linked lists
Answer:
- 98.
Dutch national flag sorting problem
Answer:
- 99.
Insert an interval into a list of sorted disjoint intervals
Answer:
- 100.
Implement a queue using a linked list
Answer:
- 101.
Quickly calculate the cube root of 6 digit numbers
Answer:
- 102.
Implement pow(a,b) without multiplication or division
Answer:
- 103.
What is the new keyword in JavaScript?
Answer:
- 104.
Explain Prototype Inheritance in JavaScript?
Answer:
- 105.
What does the term Transpiling stand for?
Answer:
- 106.
Can you give an example for destructuring an object or an array in ES6?
Answer:
- 107.
Explain the Prototype Design Pattern
Answer:
- 108.
Describe the JS module design pattern
Answer:
- 109.
Can you describe the main difference between a .forEach loop and a .map() loop and why you would pick one versus the other?
Answer:
- 110.
Explain what is Hoisting in Javascript
Answer:
- 111.
How can you share code between files?
Answer:
- 112.
What are the actual uses of ES6 WeakMap?
Answer:
- 113.
Explain difference between: function Person(){}, var person = Person(), and var person = new Person()?
Answer:
- 114.
Check if a given string is a isomorphic
Answer:
- 115.
What is Hoisting in JavaScript?
Answer:
- 116.
When should you NOT use arrow functions in ES6? Name three or more cases.
Answer:
- 117.
What's the difference between a variable that is: null, undefined or undeclared? How would you go about checking for any of these states?
Answer:
- 118.
What is the Temporal Dead Zone in ES6?
Answer:
- 119.
Explain how JSONP works (and how it's not really Ajax)
Answer:
- 120.
Could you compare usage of Module Pattern vs Constructor/Prototype pattern?
Answer:
- 121.
What's the difference between ES6 Map and WeakMap?
Answer:
- 122.
What is the difference between the await keyword and the yield keyword?
Answer:
- 123.
Compare Async/Await and Generators usage to achive same functionality
Answer:
- 124.
How to deep-freeze object in JavaScript?
Answer:
- 125.
Is it possible to reset an ECMAScript 6 generator to its initial state?
Answer:
- 126.
Is JavaScript a pass-by-reference or pass-by-value language?
Answer:
- 127.
In JavaScript, why is the this operator inconsistent?
Answer:
- 128.
Can you give an example of a curry function and why this syntax offers an advantage?
Answer:
- 129.
Write a recursive function that performs a binary search
Answer:
- 130.
When would you use the bind function?
Answer:
- 131.
Create a function that will evaluate if a given expression has balanced parentheses using stacks
Answer:
- 132.
How would you create a private variable in JavaScript?
Answer:
- 133.
How would you add your own method to the Array object so the following code would work?
Answer:
- 134.
How does the this keyword work? Provide some code examples
Answer:
- 135.
What will be the output of the following code?
Answer:
- 136.
Given an integer, determine if it is a power of 2. If so, return that number, else return -1
Answer:
- 137.
What will the following code output?
Answer:
- 138.
What will be the output of the following code?
Answer:
- 139.
Explain why the following doesn't work as an IIFE. What needs to be changed to properly make it an IIFE?
Answer:
- 140.
What is Closure in JavaScript? Provide an example
Answer:
- 141.
Transform Word
Answer:
- 142.
Describe the Revealing Module Pattern design pattern
Answer:
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