Page 234 - Web Applications (803) Class 12
P. 234
18. Write a statement in JavaScript to declare a variable ‘Sum’ and initialise it with 10. [2022 T2]
Ans. var Sum = 10;
19. How many times will the following loop run? [2022 T2]
for (var i = 0; i < = 5; i ++)
{
……
}
Ans. It runs for i values 0, 1, 2, 3, 4, and 5, which is a total of six iterations.
20. Write the examples of any two logical operators you know. [2022 T2]
Ans. i. AND Operator (&&), ii. OR Operator (||)
21. Write any two ways to convert a string to a number in JavaScript. [2022 T2]
Ans. In JavaScript, you can convert a string to a number using the following two common methods:
i. Using parseInt() or parseFloat(): parseInt(string) converts a string to an integer (parseFloat converts to
float), parsing it until a non-numeric character is encountered.
ii. Using the Number() constructor: JavaScript provides the Number() constructor that can be used to
explicitly convert a string to a number. It can handle both integers and floating-point numbers.
22. Write a command to declare an array ‘AR’. Explain any one property of an array. [2022 T2]
Ans. To declare an array named ‘AR’ in JavaScript, you can use the following command: var AR = [];
One important property of an array in JavaScript is its length property. The length property indicates the number
of elements in the array.
Example:
var AR = [10, 20, 30, 40, 50];
document.write(AR.length);
// Outputs: 5
23. What do you understand by the properties and methods of an object? [2022 T2]
Ans. An object in JavaScript is a collection of properties and methods. Properties are like attributes/characteristics of
an object, and methods are like functions that can be performed on an object.
Example:
const person = {
name: "Abhira",
age: 22,
display() {
document.write("Hello " + this.name);
}
};
const P1 = person;
P1.display();
In this example, the name and age properties are attributes of the person object, and the display() method is a
function that can be performed on the person object.
232 Touchpad Web Applications-XII

