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
How do you concatenate strings in JavaScript?
A). Using the + operator
B). Using the - operator
C). Using the * operator
D). Using the / operator
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 '''
What is the purpose of the 'this' keyword in JavaScript?
A). To refer to the current HTML element
B). To refer to the current JavaScript file
C). To refer to the current object
D). To refer to the current function
What is the purpose of the 'return' statement in a JavaScript function?
A). To end the function execution
B). To return a value from the function
C). To print a value to the console
D). To declare a variable
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
How do you access the last element of a JavaScript array?
A). colors[colors.length - 1];
B). colors.last();
C). colors[-1];
D). colors.getLast();
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};
Which statement correctly declares a JavaScript function?
A). function greet() {}
B). const greet = function() {}
C). const greet = () => {}
D). const greet = {}
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();