6) How can you differentiate between two words "var" and "let" keyword?
7) Negative Infinity?
When we divide any negative number with zero, the number's is called Negative infinity.
For e.g. -4/0
8) What do "2"+3+7 evaluate to?
9) What do 2+6+"7" evaluate to?
10) How you can differentiate between "==" and "==="?
|!ERROR! unexpected operator '='||!ERROR! unexpected operator '='|
|Only check equality in value||If the two variables or types are not identical, it returns false|
|Refers to equal||Refers to identical equal or strict equality operator|
|While comparing == also do type comparison||Not do type conversion while comparing|
The variable that is not present in a program or the variables that are not declared are known as undeclared variables. Runtime error may be occurring if we are trying to execute a program with undeclared variables.
Undeclared variables are those variables that are declared but not any value have been provided. An undefined value may be return if we try to execute a program containing undeclared variable
A prompt box is a box containing label box, text box and various another box to allow users to enter any input whether it is text or numerical .
"This" Keyword provides the reference to the object from where it was called. Generally, "This" keyword represents current content.
14) If we want to remove the focus from the specified object which function can be used?
Blur Function can be used.
|Popup Boxes||The method used to create Pop Boxes|
18) Unshift method?
This method is identical to push() method and return the length of an array. This method can be used when there is a requirement for insertion of any item to a front of an array.
push() method can be used.
There are mainly two techniques for Array Creation.
a) First method is to declare Array:
var colors = new Array();
Add item in Array:-
colors  = "Red";
colors  = "yellow";
colors  = "black";
b) Second Method is
var colors = new Array("Red", "Yellow", "Black");
22) If there is an Array name as "colors" which contain four elements, then how Fourth element can be printed?
When the argument does not contain a number, isNaN function returns true.
document.write(isNaN("Friends")+ "<br>" );
document.write(isNaN(567)+ "<br>" );
Output will be:
You need to add one line in Head Section to redirect a URL.
Output of following statements
console.log(4 + '4'); //44
console.log(4 â '4'); //0
25) Which method returns the character at specified index?
26) Role of navigator.app Version string ?
With this, OS of the client machine can be detected.
28) Which function can be used to convert URL into their Hex coding?
encodeURL() can be used.
30) Is alert box and confirmation box are similar?
No, they are not same. The difference found in the button. An alert box contains only one OK button whereas a confirmation box contains two buttons i.e. Cancel and OK.