Page 233 - Web Applications (803) Class 12
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10. Write any two characteristics of a ‘typeof’ operator in JavaScript. [2023]
Ans. In JavaScript, the typeof operator has two characteristics:
• It's a unary operator, which implies it only accepts one operand. Any type of operand can be used.
• It returns a string showing the operand's data type. "number", "string", "boolean", "object", "function",
"undefined", and "symbol" are all valid return values.
11. Differentiate between % operator and / operator in JavaScript with the help of an example. [2023]
Ans. In JavaScript, the % operator is the modulus operator, which returns the remainder of a division operation. The
division operator, represented by the / operator, returns the quotient of a division operation.
Example: 10% 3 => will give answer as 1
10/3 => will give answer as 3.333
12. Explain parseInt() and isNaN(), giving one example of each. [2023]
Ans. isNaN() returns a boolean if a value is not a valid number. parseInt() attempts to extract an integer from a string
and returns either the integer or NaN if it is unable to do so.
var num1 = parseInt("20"); // This will return 20
var num2 = parseInt("hello"); // This will return NaN
var num3 = isNaN(num1); // This will return false
13. A java script file has ____ extension. [2022 T1]
(a) .java (b) .js
(c) .jscript (d) .jsr
Ans. (b) .js
14. Document object uses its ____ method to output some text to the page document. [2022 T1]
(a) print() (b) write()
(c) display() (d) cout()
Ans. (b) write()
15. Identify the operators that check if the value of two operands are equal or not. If values are not equal then
condition becomes true. [2022 T1]
(a) == (b) !=
(c) Not equal (d) Equal to
Ans. (a) ==
16. Statement I: Java script is a server-side language, which means all the action occurs on the client’s (reader’s) side
of things. This means that no trips to the server are required for JavaScript to kick into operation, which would
slow down the process. [2022 T1]
Statement II: JavaScript is integrated into the browsing environment, which means they can get information
about the browser and HTML page and modify this information, thus how things are presented on your screen?
Identify the correct option.
(a) Only statement I is correct (b) Only statement II is correct
(c) Both statements I and II are correct (d) Both statements I and II are wrong
Ans. (d) Both statements I and II are wrong
17. Write the output of the following code: [2022 T2]
NaN + 5
Ans. NaN
Web Scripting—JavaScript 231

