Prove your skills in c. Pass this exam to earn your certificate.

What is the output of the following code?

console.log(0.1 + 0.2 === 0.3);

Which of the following is NOT a valid way to define an object property in JavaScript?

How does JavaScript handle asynchronous operations?

What does the following code return?

console.log(typeof null);

Which of the following is NOT a JavaScript data type?

What is the output of the following code?

console.log([] + []);

What will be logged to the console?

let x = (function() { return 5 })();
console.log(typeof x);

What happens when you use the 'use strict' directive?

Which method is used to remove the last element from an array and return it?

What is the result of the following expression?

console.log(typeof NaN);

What is the output of the following code?

console.log('5' - 3);

What is the result of the following code?

console.log('5' + 3);

Which operator is used to compare both value and type in JavaScript?

What does the 'this' keyword refer to in a regular function (non-strict mode) when invoked without an object?

What is the output of the code:

console.log(2 ** 3);

Which of the following is a feature of ES6?

What will the code output?

console.log(typeof function(){});

What will be the output of

console.log([] instanceof Array);

Which method converts a JSON string to a JavaScript object?

What is the purpose of the JavaScript 'bind()' method?

Which of the following can be used to create an object in JavaScript?

What is the output of

console.log(0 == false);

What is the output of

console.log(0 === false);

Which method is used to merge two or more arrays in JavaScript?

What is the output of the following code?

console.log(typeof typeof 1);

In JavaScript, what does the 'spread operator' (...) do?

What does the 'void' operator do in JavaScript?

Which statement about JavaScript hoisting is correct?

What is the purpose of using arrow functions in JavaScript?

What will the code output?

console.log(1 + '1');

Which of the following is a way to create a promise in JavaScript?

What is the output of this code?

console.log([1, 2, 3].map(x => x * 2));

Which method is used to filter elements in an array?

What does the Array.prototype.reduce() method do?

What will the following code output?

console.log(typeof NaN === 'number');

What is the output of the code:

console.log(parseInt('08'));

Which built-in method returns the index within the calling String of the first occurrence of a specified value?

What will the following code output?

console.log(true + false);

What is the output of this code snippet?

console.log([,].length);

Which of the following is a correct way to check if a variable 'x' is an array?

What does the method Array.prototype.slice() do?

What is the output of the following code?

console.log(!!'');

What is the output of the following code?

console.log(!!'hello');

What does the function Array.isArray() do?

Which of the following is NOT a valid JavaScript loop construct?

What is the output of the following code?

console.log(3 > 2 > 1);

Which keyword is used to declare a variable that cannot be reassigned?

What is the output of

console.log(typeof undefined);

What does the 'delete' operator do in JavaScript?

Which method can be used to merge two objects in ES6?

What is the result of

console.log('10' * '5');

What is the output of the following code snippet?

console.log([1, 2, 3].join('-'));

What does the 'typeof' operator return when called on a function?

What is the output of the code:

console.log(!!null);

Which method is used to add one or more elements to the beginning of an array?

What is the output of the following code?

console.log((true && false) || true);

What will the following code output?

console.log('Hello' instanceof String);

What is the output of this code snippet?

let a = [1, 2, 3];
a[10] = 99;
console.log(a.length);

JavaScript

What is the output of the following code? console.log(0.1 + 0.2 === 0.3);