Quiz – JavaScript

What is the value of [ 1, 2, 3 ].at( -1 )?

Which of the following is hoisted?

What will this code snippet print:

const numbers = [ 1, 3, 5, 7, 9 ];

numbers.pop();

console.log(numbers);

What will this code snippet print:

    let name = ”hello”;

    name.toUpperCase();

    console.log(name);

What will this code snippet print:

const strings = [“E”, “N”, “J”, “O”, “Y”];

const reduced = strings.reduce((p, o) => p.concat(o));

console.log(reduced);

Is JavaScript multithreaded?

Is JavaScript synchronous by nature?

What are the possible states of a promise?

Which of the following can be used to run code when a promise is fulfilled?

Which of the following can be used to run code when a promise is rejected?

How can we pause code execution until a promise is not fulfilled/rejected?

Find the mistake in the code snippet below:

function getData() {

    try {

    const data = await fetch(URL)

    } catch (err) {

    console.error(‘Something wrong happened’)

    }

}

What is the initial state of a promise?

Which of the following have the type number

If var x = NaN, select the statement(s) which are correct

Which of the following code snippets will log “Hello”:

Which among the following is the slowest to run assuming that we are targeting the same element?

Which of the following expression(s) will store “Hello World” in x?

Which of the following will return false?

Which of the following data types are mutable in JavaScript?

Which of the following methods can be used to change the ID of an element?

The Event Queue stores codes that

What is the alternative for reject when creating a new promise?

What will the code below log:

var promise = new Promise(function(resolve, reject) {

     resolve(“OK”);

});

var promise2 = promise.then(function(data) {

     return data;

});

var promise3 = promise.then(function(data) {

     return data;

});

console.log(p2 === p3);

What is the function that’s passed to Promise() as an argument called?

Can the return keyword be used outside a function?

What are the two arguments that setTimeout() expects?

The delay in setTimeout is in?

Which of the code snippets below will multiply two numbers together?

Can we use == or === to compare objects in JavaScript?