Which statement correctly declares a JavaScript object?
A). let person = {name: 'John', age: 30};
B). const person = ('name' => 'John', 'age' => 30);
C). const person = ['name', 'John', 'age', 30];
D). var person = {name: 'John', age: 30};
How can you prevent a JavaScript function from executing immediately?
A). Using async/await
B). Using the defer attribute in HTML script tag
C). Wrapping the function in parentheses
D). Using the setTimeout function
What is the purpose of the 'constructor' method in a JavaScript class?
A). To create new instances of the class
B). To initialize class properties
C). To define class methods
D). To define class inheritance
Which method is used to remove the last element from a JavaScript array?
A). colors.pop();
B). colors.removeLast();
C). colors.splice(-1, 1);
D). colors.deleteLast();
How can you convert a string to a number in JavaScript?
A). parseInt('10')
B). parseFloat('10.5')
C). Number('10')
D). All of the above
Which statement correctly declares a JavaScript module?
A). export function myFunc() {}
B). const myModule = function() {}
C). module.exports = myModule;
D). import myModule from './myModule.js';
Which statement correctly declares a JavaScript array?
A). let colors = ['red', 'green'];
B). const colors = {'red', 'green'};
C). const colors = ['red', 'green'];
D). var colors = ('red', 'green');
How can you add a new element to the end of a JavaScript array?
A). colors.push('blue');
B). colors.add('blue');
C). colors.insert('blue', colors.length);
D). colors[colors.length] = 'blue';
What is the purpose of the 'typeof' operator in JavaScript?
A). To check if a variable is defined
B). To check the data type of a variable
C). To assign a data type to a variable
D). To increment the value of a variable
How can you comment a single line of code in JavaScript?
A). // This is a comment
B). <!-- This is a comment -->
C). /* This is a comment */
D). ''' This is a comment '''