JavaScript Array and Function Test(1st)

What is the opposite approach to the lexical scoping?

1 Mark(s)

Generic scoping
Dynamic scoping
Static scoping
Literal scoping

Consider the following code snippet :

var a = []; 
a.unshift(1); 
a.unshift(22);
a.shift(); 
a.unshift(3,[4,5]); 
a.shift(); 
a.shift();
a.shift();

The final output for the shift() is

Consider the following code snippet :

var a = []; 
a.unshift(1); 
a.unshift(22);
a.shift(); 
a.unshift(3,[4,5]); 
a.shift(); 
a.shift();
a.shift();

The final output for the shift() is

1 Mark(s)

1
Exception is thrown
[3,4,5]
[4,5]

What will happen if reverse() and join() methods are used simultaneously ?

1 Mark(s)

Reverses and stores in the same array
Reverses and concatenates the elements of the array
Reverses
All of the mentioned

What will happen if a return statement does not have an associated expression?

1 Mark(s)

None of the mentioned
It will throw an exception
It returns the value 0
It returns the undefined value

Consider the following code snippet :

var grand_Total=eval("10*10+5");

The output for the above statement would be :

Consider the following code snippet :

var grand_Total=eval("10*10+5");

The output for the above statement would be :

1 Mark(s)

Exception is thrown
105 as a string
10*10+5
105 as an integer value

What is the purpose of a return statement in a function?

1 Mark(s)

Returns the value and stops executing the function
Returns the value and continues executing rest of the statements, if any
Returns the value and stops the program
Stops executing the function and returns the value

A function with no return value is called

1 Mark(s)

Procedures
Dynamic function
Static function
Method

Consider the following code snippet

function printprops(o) 
{
  for(var p in o)
  console.log(p + ": " + o[p] + "n");
}

What will the above code snippet result ?

Consider the following code snippet

function printprops(o) 
{
  for(var p in o)
  console.log(p + ": " + o[p] + "n");
}

What will the above code snippet result ?

1 Mark(s)

All of the mentioned
Prints the contents of each property of o
None of the mentioned
Returns undefined

What is the difference between the two lines given below ?

!!(obj1 && obj2);
(obj1 && obj2);

What is the difference between the two lines given below ?

!!(obj1 && obj2);
(obj1 && obj2);

1 Mark(s)

The first line results in a real boolean value whereas the second line merely checks for the existence of the objects
Both the lines checks just for the existence of the object alone
Both the lines result in a boolean value “True”
Both the lines result in a boolean value “False”

The reduce and reduceRight methods follow a common operation called

1 Mark(s)

inject and fold
fold
finger and fold
filter and fold

The primary purpose of the array map() function is that it

1 Mark(s)

maps the elements of another array into itself
passes each element of the array and returns the necessary mapped elements
passes each element of the array on which it is invoked to the function you specify, and returns an array containing the values returned by that function
None of the mentioned

Which of the following is the correct code for invoking a function without this keyword at all, and also too determine whether the strict mode is in effect?

1 Mark(s)

var strict = (function { return this; });
mode strict = (function { });
mode strict = (function() { return !this; }());
var strict = (function() { return !this; }());

Consider the following code snippet :

var tensquared = (function(x) {return x*x;}(10));

Will the above code work ?

Consider the following code snippet :

var tensquared = (function(x) {return x*x;}(10));

Will the above code work ?

1 Mark(s)

Error
Exception will be thrown
Yes, perfectly
Memory leak

Consider the following code snippet

function hypotenuse(a, b) 
{
  function square(x) 
  { 
    return x*x; 
  }
  return Math.sqrt(square(a) + square(b));
}

What does the above code result?

Consider the following code snippet

function hypotenuse(a, b) 
{
  function square(x) 
  { 
    return x*x; 
  }
  return Math.sqrt(square(a) + square(b));
}

What does the above code result?

1 Mark(s)

Sum of a and b square
None of the mentioned
Square of sum of a and b
Sum of square of a and b

If you have a function f and an object o, you can define a method named m of o with

1 Mark(s)

o.m=m.f;
o.m=f;
o=f;
o=f.m;

What kind of scoping does JavaScript use?

1 Mark(s)

Lexical
Literal
Segmental
Sequential

Consider the following code snippet :

var string2Num=parseInt("123xyz");

The result for the above code snippet would be :

Consider the following code snippet :

var string2Num=parseInt("123xyz");

The result for the above code snippet would be :

1 Mark(s)

NaN
Exception
123xyz
123

The method or operator used to identify the array is

1 Mark(s)

===
typeof
==
isarrayType()

When does the function name become optional in JavaScript?

1 Mark(s)

When the function is defined as expressions
When the function is defined as a looping statement
All of the mentioned
When the function is predefined

Consider the following code snippet :

if (!a[i]) continue ;

What is the observation made ?

Consider the following code snippet :

if (!a[i]) continue ;

What is the observation made ?

1 Mark(s)

Skips the null elements
Skips the undefined elements
Skips the non existent elements
All of the mentioned

Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?

1 Mark(s)

o.m(x) && o.m(y);
m(x,y);
o.m(x,y);
o(x,y);

Consider the following code snippet :

var a = [1,2,3,4,5];
a.slice(0,3);

What is the possible output for the above code snippet ?

Consider the following code snippet :

var a = [1,2,3,4,5];
a.slice(0,3);

What is the possible output for the above code snippet ?

1 Mark(s)

Returns [1,2,3]
Returns [1,2,3,4,5]
Returns [4,5]
Returns [1,2,3,4]

Consider the code snippet given below

var count = [1,,3];

What is the observation made?

Consider the code snippet given below

var count = [1,,3];

What is the observation made?

1 Mark(s)

The omitted value takes “undefined”
This results in an error
This results in an exception
None of the mentioned

Which of the algorithmic languages is lexical scoping standardized in?

1 Mark(s)

Ada
Modula2
All of the mentioned
Pascal

For the below mentioned code snippet:

var o = new Object();

The equivalent statement is:

For the below mentioned code snippet:

var o = new Object();

The equivalent statement is:

1 Mark(s)

var o= new Object;
Object o=new Object();
var o;
var o = Object();

Which of the following uses a lot of CPU cycles?

1 Mark(s)

Dynamically generated graphics
GUI
All of the mentioned
Statically generated graphics

The function definitions in JavaScript begins with

1 Mark(s)

Identifier and Parantheses
Identifier and Return type
Return type, Function keyword, Identifier and Parantheses
Return type and Identifier

Do functions in JavaScript necessarily return a value ?

1 Mark(s)

It is mandatory
Few functions return values by default
Not necessary
All of the mentioned

What is the purpose of the dynamic scoping?

1 Mark(s)

Variables can be declared outside the scope
Variables cannot be declared outside the scope
None of the mentioned
Variables must be declared outside the scope

What is the fundamental rule of lexical scoping?

1 Mark(s)

Functions are declared in the scope
None of the mentioned
All of the mentioned
Functions are executed using scope chain

Consider the following code snippet :

var c = counter(), d = counter(); 
function constfuncs() 
{
    var funcs = [];
    for(var i = 0; i < 10; i++)
        funcs[i] = function() { return i; };
    return funcs;
}
var funcs = constfuncs();
funcs[5]()

What does the last statement return ?

Consider the following code snippet :

var c = counter(), d = counter(); 
function constfuncs() 
{
    var funcs = [];
    for(var i = 0; i < 10; i++)
        funcs[i] = function() { return i; };
    return funcs;
}
var funcs = constfuncs();
funcs[5]()

What does the last statement return ?

1 Mark(s)

None of the mentioned
0
10
9

What must be done in order to implement Lexical Scoping?

1 Mark(s)

Reference the current scope chain
Get the object
Dereference the current scope chain
None of the mentioned

Which of the following are examples of closures?

1 Mark(s)

Variables
Objects
All of the mentioned
Functions

Consider the following code snippet :

var c = counter(), d = counter(); 
c.count()
d.count() 
c.reset() 
c.count() 
d.count()

The state stored in d is :

Consider the following code snippet :

var c = counter(), d = counter(); 
c.count()
d.count() 
c.reset() 
c.count() 
d.count()

The state stored in d is :

1 Mark(s)

Undefined
0
1
Null

What is a closure?

1 Mark(s)

Scope where function’s variables are resolved
Function objects
Both Function objects and Scope where function’s variables are resolved
None of the mentioned

The pop() method of the array does which of the following task ?

1 Mark(s)

None of the mentioned
increments the total length by 1
decrements the total length by 1
prints the first element but no effect on the length

Consider the following code snippet

var a1 = [,,,]; 
var a2 = new Array(3); 
0 in a1 
0 in a2

The result would be

Consider the following code snippet

var a1 = [,,,]; 
var a2 = new Array(3); 
0 in a1 
0 in a2

The result would be

1 Mark(s)

false true
true true
true false
false true

Consider the following code snippet :

var scope = "global scope";
function checkscope() {
var scope = "local scope"; 
function f() 
{ 
     return scope; 
}
return f;

What is the function of the above code snippet?

Consider the following code snippet :

var scope = "global scope";
function checkscope() {
var scope = "local scope"; 
function f() 
{ 
     return scope; 
}
return f;

What is the function of the above code snippet?

1 Mark(s)

None of the mentioned
Returns exception
Returns the value in scope
Returns value null

JavaScript Array and Function Test(1st) : Question 1 of 38