javascript part 1

Question 1

java is ____ type of language

Answer 1

strong

Question 2

javascript is _____ type of language

Answer 2

weak

Question 3

Supports object-oriented and imperative programming styles was standardised as ECMScript 1. True or False?

Answer 3

False. it is ECMAScript

Question 4

What are the 6 primitive type of javascript?

Answer 4

undefined 
variables
null value denoting intentional lack of a value
Boolean 
Number 
String

Question 5

anon = function() { print(‘I am hii’); }

if you want to use this function. what would you type?

Answer 5

anon();

Question 6

anon = function() { print(‘oh’); }

What type of function is this?

Answer 6

Anonymus function. it would be defined if we had written it as:
function anon()

Question 7

method to return character at index N

Answer 7

charAt(N)

Question 8

method to returns index of S in string

Answer 8

indexOf(S)

Question 9

method to returns last index of S in string

Answer 9

lastIndexOf(S)

Question 10

what does the .length method do?

Answer 10

returns length of string

Question 11

method to returns array of substrings separated by S

Answer 11

Split(S)

Question 12

substring(M) will output:

Answer 12

returns substring from index to end

Question 13

substring(M, N) will output:

Answer 13

returns substring from element M to N.

Question 14

how to add two strings without the + symbol

Answer 14

a.concat(b)

Question 15

let arr = [‘a’, 2, ‘c’];
alert( arr[9] );
what will be the output?

Answer 15

array out of boundary.

Question 16

what method would you use to get an array without the repeated elements. for example:
arry = [2,6,2,5,7];
will output
arry = [2,6,5,7];

Answer 16

filter()

Question 17

what does the map() function do?

Answer 17

map function will apply function to each element.
for example we have an array 1,2,3,4
and want to add 1 to all the elements. we would use the map function

Question 18

method that applies accumulator/concatenator across array elements

Answer 18

reduce()

Question 19

javascript objects are primative. True or False?

Answer 19

False. they are non primitaive

Question 20

javascript objects have ____ that are also objects and they inherit properties and methods from that.

Answer 20

prototype

Question 21

All objects inherit from prototype are called?

Answer 21

Object.prototype.

Question 22

ES 6 introduced class notation to JavaScript where

Answer 22

classes are syntactic sugar over prototype-based objects and no new object-oriented model is introduced

Question 23

javacript is single threaded. True or false?

Answer 23

False. It is multithreaded