Using a web page and Active X objects
3. Explain the difference between “==” and “===”?
Ans. “==” checks only for equality in value whereas “===” is a stricter equality test and returns false
if either the value or the type of the two variables are different.
4. What would be the result of 3+2+"7"?
Ans. Since 3 and 2 are integers, they will be added numerically. And since 7 is a string, its
concatenation will be done. So the result would be 57.
5. Explain how to detect the operating system on the client machine?
Ans. In order to detect the operating system on the client machine, the navigator.appVersion string
(property) should be used.
Ans. The NULL value is used to represent no value or no object. It implies no object or null string, no
valid boolean value, no number and no array object.
7. What is the function of delete operator?
Ans. The functionality of delete operator is used to delete all variables and objects in a program but it cannot delete variables declared with VAR keyword.
Ans. Alert, Confirm and, Prompt
9. What is the use of Void(0)?
Ans. Void(0) is used to prevent the page from refreshing and parameter "zero" is passed
Void(0) is used to call another method without refreshing the page.
Ans. Undefined value means the Variable used in the code doesn’t exist
Variable is not assigned to any value Property doesn’t exist