JavaScript 1.8 Test
Analyze the
following code snippet. What will be the output of this code?
<html>
<body>
<script type="text/javascript">
var str = "The drain of the plane is plain";
var patt1 =/ain/g;
document.write(str.match(patt1));
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "The drain of the plane is plain";
var patt1 =/ain/g;
document.write(str.match(patt1));
</script>
</body>
</html>
a. 1
b. ain
c. 7,29
d. 7
e. ain,ain
Which of the
following is the correct syntactical representation of a generator expression
in JavaScript?
a. var doubles = [i * 2 for
(i in it)];
b. var doubles = [i * 2 for
[i in it]];
c. var doubles = (i * 2
for (i in it));
d. var doubles = {i * 2 for
(i in it)};
What is the output
of the following JavaScript code?
s2 = new String("2 + 2")
document.write(eval(s2));
s2 = new String("2 + 2")
document.write(eval(s2));
a. 4
b. 2+2
c. Error
d. None of the above
Consider the
following code snippet. Which of the given options would be used in E4X to
change the color of the descendant node chair?
var element = <Home>
<Room>
<Furniture>
<chair color="Brown"/>
</Furniture>
</Room>
</Home>
var element = <Home>
<Room>
<Furniture>
<chair color="Brown"/>
</Furniture>
</Room>
</Home>
a.
element.chair.color="light brown"
b. element.chair.@color="light
brown"
c.
element..chair.@color="light brown"
Consider the code
snippet below. Which of the given options represents the correct sequence of
outputs when this code is executed in E4X?
var p1 = <p>Kibology for all.</p>;
alert(p1.name().uri);
default xml namespace = 'http://www.w3.org/1999/xhtml';
var p2 = <p>Kibology for all.</p>;
alert(p2.name().uri);
default xml namespace = '';
var p3 = <p>Kibology for all.</p>;
alert(p3.name().uri);
var p1 = <p>Kibology for all.</p>;
alert(p1.name().uri);
default xml namespace = 'http://www.w3.org/1999/xhtml';
var p2 = <p>Kibology for all.</p>;
alert(p2.name().uri);
default xml namespace = '';
var p3 = <p>Kibology for all.</p>;
alert(p3.name().uri);
a.
'',http://www.w3.org/1999/xhtml,''
b. '','',''
d. None of the above
Which of the
following is not a valid JavaScript operator?
a. *=
b. /=
c. %=
d. ^+
Which of the
following is not a valid String method?
a. link()
b. italics()
c. str()
d. sup()
Which of the
following methods is used to add and/or remove elements from an array and
modify them in place?
a. push
b. slice
c. join
d. splice
In JavaScript, the
encodeURI() function is used to encode special characters. Which of the
following special characters is/are an exception to that rule?
a. £
b. €
c. @
d. $
e. a and b
f. c and d
Which of the
following is not a valid Date Object method in JavaScript?
a. parse()
b. setDay()
c. setTime()
d. valueOf()
Which of the
following results is returned by the JavaScript operator "typeof" for
the keyword "null"?
a. function
b. object
c. string
d. number
Which of the
following can be used to create attribute values by placing variables and
expressions within them?
a. []
b. ()
c. {}
d. <>
What will the
function NaN return for the condition NaN == NaN?
a. true
b. false
c. error
d. 0
Which of the
following modifiers must be set if we use the Javascript lastIndex Object
Property during pattern matching?
a. i
b. m
c. g
d. s
Which of the
following two JavaScript code snippets is the more efficient and why?
CODE SNIPPET 1
<script language="javascript">
for(i=0;i<document.images.length;i++)
document.images[i].src="blank.gif";
</script>
CODE SNIPPET 2
<script language="javascript">
var theimages = document.images;
for(i=0;i<theimages.length;i++)
theimages[i].src="blank.gif";
</script>
CODE SNIPPET 1
<script language="javascript">
for(i=0;i<document.images.length;i++)
document.images[i].src="blank.gif";
</script>
CODE SNIPPET 2
<script language="javascript">
var theimages = document.images;
for(i=0;i<theimages.length;i++)
theimages[i].src="blank.gif";
</script>
a. Both codes are equally
efficient.
b. The first code is more
efficient because it contains less code.
c. The first code is more efficient
because it employs object caching.
d. The second code is
more efficient because it employs object caching.
Which of the
following is used to solve the problem of enumerations in JavaScript?
a. let
b. Regex
c. Generators
d. E4X
Is the following
statement regarding expression closures in JavaScript true or false?
The syntax function(x) {return x*x;} can be written as function(x) x*x.
The syntax function(x) {return x*x;} can be written as function(x) x*x.
a. True
b. False
Which of the given
options represents the correct length when alert(Emp..*.length()); is applied
to the following code?
var Emp = <Emp>
<name>Mark</name>
<likes>
<os>Linux</os>
<browser>Firefox</browser>
<language>JavaScript</language>
<language>Python</language>
</likes>
</Emp>
var Emp = <Emp>
<name>Mark</name>
<likes>
<os>Linux</os>
<browser>Firefox</browser>
<language>JavaScript</language>
<language>Python</language>
</likes>
</Emp>
a. 11
b. 5
c. 6
d. 12
Analyze the
following code snippet. What will be the output of this code?
<html>
<body>
<script type="text/javascript">
var str = "Visit Gardens(now)";
var patt1 = new RegExp("(now)", "g");
patt1.test(str);
document.write(RegExp.lastParen);
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "Visit Gardens(now)";
var patt1 = new RegExp("(now)", "g");
patt1.test(str);
document.write(RegExp.lastParen);
</script>
</body>
</html>
a. now
b. (now)
c. 15
d. 19
Which of the
following is the correct way to create an XML object in E4X?
a. var languages = new
XML('JavaScriptPython');
b. var languages XML = new
XML('JavaScriptPython');
c. var languages =
JavaScript
Python
;
JavaScript
Python
;
d. All of the above are
correct.
e. a and c
f. b and c
Which of the
following Array methods in JavaScript runs a function on every item in the
Array and collects the result from previous calls, but in reverse?
a. reduce()
b. reduceRight()
c. reverse()
d. pop()
Which of the
following can be achieved using JavaScript?
a. Reading or writing from
external files
b. Accessing or modifying
browser settings
c. Launching the default
email application of the client
d. All of the above can
be achieved using JavaScript.
Which of the
following objects is the top-level object in the JavaScript hierarchy?
a. Navigator
b. Screen
c. Window
d. Document
Which of the
following Javascript Regular Expression modifiers finds one or more occurrences
of a specific character in a string?
a. ?
b. *
c. +
d. #
Which of the
following is the correct syntax for using the Javascript exec() object method?
a. RegExpObject.exec()
b.
RegExpObject.exec(string)
c.
RegExpObject.exec(parameter1,parameter2)
d. None of the above
Analyze the
following code using the source property of Regular Expressions. What will be
the output of the below code snippet?
<html>
<body>
<script type="text/javascript">
var str = "Visit Garden\Showcase";
var patt1 = new RegExp("en\S","g");
document.write("The regular expression is: " + patt1.source);
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "Visit Garden\Showcase";
var patt1 = new RegExp("en\S","g");
document.write("The regular expression is: " + patt1.source);
</script>
</body>
</html>
a. The regular expression
is: en\S
b. The regular expression
is: 11
c. The regular expression
is: enS
d. The regular expression
is: 10
Which of the
following options can be used for adding direct support for XML to JavaScript?
a. E4X
b. regex
c. Generators and Iterators
d. let
Which of the
following options is used to access the attributes in E4X?
a. @
b. ::
c. #
d. *
Which of the
following statements regarding let in JavaScript is not correct?
a. The let definition
defines variables whose scope is constrained to the block in which they're
defined. This syntax is very much like the syntax used for var.
b. The let expression lets
you establish variables scoped only to a single expression.
c. The let keyword
provides a way to associate values with variables within the scope of a block,
and affects the values of like-named variables outside the block.
d. You can use let to
establish variables that exist only within the context of a for loop.
Which of the
following are not global methods and properties in E4X?
a. ignoreComments
b. ignoreWhiteSpace
c. setName()
d. setNamespace()
e. a and b
f. c and d
What will be the
output of the following code?
var x = 5;
var y = 0;
document.write( let(x = x + 10, y = 12) x+y + ",");
document.write(x+y);
var x = 5;
var y = 0;
document.write( let(x = x + 10, y = 12) x+y + ",");
document.write(x+y);
a. 27,5
b. 22,5
c. 27,22
d. None of the above
Which of the
following is not a valid method in generator-iterator objects in JavaScript?
a. send()
b. throw()
c. next()
d. stop()
Using the concept
of "iterators" and "generators" in JavaScript, what will be
the output of the following code?
function testGenerator()
{
yield "first";
document.write("step1");
yield "second";
document.write("step2");
yield "third";
document.write("step3");
}
var g = testGenerator();
document.write(g.next());
document.write(g.next());
function testGenerator()
{
yield "first";
document.write("step1");
yield "second";
document.write("step2");
yield "third";
document.write("step3");
}
var g = testGenerator();
document.write(g.next());
document.write(g.next());
a. firststep1second
b. step1step2
c. step1
d. step1step2step3
Which of the
following DOM objects can be used to determine the resolution of the screen?
a. It is not possible to
determine the resolution of the screen.
b. Screen object
c. Document object
d. Window object
e. None of the above
Analyze the
following code snippet. What will be the output of this code?
<html>
<body>
<script type="text/javascript">
var str = "The rose";
var patt1 = new RegExp("rose", "g");
patt1.test(str);
document.write("rose found. index now at: " + patt1.lastIndex);
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "The rose";
var patt1 = new RegExp("rose", "g");
patt1.test(str);
document.write("rose found. index now at: " + patt1.lastIndex);
</script>
</body>
</html>
a. rose found. index now at:
5
b. rose found. index now at:
4
c. rose found. index now
at: 8
d. No output
Which of the
following options can be used to delete a child node of an XML object in E4X?
a. delete xmlobject.child;
b. delete
xmlobject.child[0];
c. delete
xmlobject.@attribute;
d. All of the above
Analyze the
following code snippet, which uses a Javascript Regular Expression Character
Set. What will be the output of this code?
<html>
<body>
<script type="text/javascript">
var str = "Is this enough?";
var patt1 = new RegExp("[^A-J]");
var result = str.match(patt1);
document.write(result);
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "Is this enough?";
var patt1 = new RegExp("[^A-J]");
var result = str.match(patt1);
document.write(result);
</script>
</body>
</html>
a. I
b. Is
c. s
d. I,s,
Consider the code
below. What will be the final value of the variable "apt"?
var apt=2;
apt=apt<<2;
var apt=2;
apt=apt<<2;
a. 2
b. 4
c. 6
d. 8
e. 16
Is the following
statement true or false?
A function becomes a generator if it contains one or more yield statements.
A function becomes a generator if it contains one or more yield statements.
a. True
b. False
What does the
following JavaScript code do?
<html>
<body>
<script type="text/javascript">
function validate()
{
var chk="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
var ok="yes";
var temp;
var field1=document.getElementById("t1");
var field=field1.value.substring(field1.value.length-1,field1.value.length);
if(chk.indexOf(field)=="-1")
{
alert("error");
field1.value=(field1.value).slice(0,field1.value.length-1);
}
}
</script>
<input type="text" id="t1" onkeyup="validate()" onkeypress ="validate()"/>
</body>
</html>
<html>
<body>
<script type="text/javascript">
function validate()
{
var chk="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
var ok="yes";
var temp;
var field1=document.getElementById("t1");
var field=field1.value.substring(field1.value.length-1,field1.value.length);
if(chk.indexOf(field)=="-1")
{
alert("error");
field1.value=(field1.value).slice(0,field1.value.length-1);
}
}
</script>
<input type="text" id="t1" onkeyup="validate()" onkeypress ="validate()"/>
</body>
</html>
a. The code will cause an
error alert to be displayed if a numeric character is entered, and the numeric
character is removed.
b. The code will cause an
error alert to be displayed if a non-numeric character is entered, and the
non-numeric character is removed.
c. The code will cause an
error alert to be displayed if a numeric character is entered, and the value of
textbox is reset.
d. The code will cause an
error alert to be displayed if a non-numeric character is entered, and the
value of textbox is reset.
Analyze the
following code snippet. What will be the output of this code?
<html>
<body>
<script type="text/javascript">
var str = "Visit Gardens(now)";
var patt1 = new RegExp("(now)", "g");
patt1.test(str);
document.write(RegExp.lastParen);
</script>
</body>
</html>
<html>
<body>
<script type="text/javascript">
var str = "Visit Gardens(now)";
var patt1 = new RegExp("(now)", "g");
patt1.test(str);
document.write(RegExp.lastParen);
</script>
</body>
</html>
a. no
b. (no)
c. 15
d. 19
Which of the
following is the correct method for getting the date of February 1 of the
current year into a variable called "newDate"?
a. var d = new Date();
newDate=new Date(d.getFullYear(), 1, 2);
newDate=new Date(d.getFullYear(), 1, 2);
b. var d = new Date();
newDate=new Date(d.getFullYear(), 2, 1);
newDate=new Date(d.getFullYear(), 2, 1);
c. var d = new Date();
newDate=new Date(d.getFullYear(), 1, 1);
newDate=new Date(d.getFullYear(), 1, 1);
d. var d = new Date();
newDate= (d.getFullYear(), 1, 1);
newDate= (d.getFullYear(), 1, 1);
Which of the
following can be used to create attribute values by placing variables and
expressions within them?
a. []
b. ()
c. {}
d. <>
Which of the
following Javascript Regular Expression Character Classes finds any non-digit
character in a given string?
a. \W
b. \S
c. \B
d. \D
Which of the
following objects in JavaScript contains the collection called
"plugins"?
a. Location
b. Window
c. Screen
d. Navigator
Which of the
following Javascript Regular Expression object methods is used to search a string
for a specified value and return the result as true or false?
a. exec()
b. compile()
c. return()
d. test()
Which of the
following methods is not a valid Array object method in JavaScript?
a. reverse
b. shift
c. unshift
d. splice
e. All of the above are
valid.
In an HTML page,
the form tag is defined as follows:
<form onsubmit="return Validate()" action="http://www.mysite.com/">
The validate() function is intended to prevent the form from being submitted if the name field in the form is empty. What will the validate() function look like?
<form onsubmit="return Validate()" action="http://www.mysite.com/">
The validate() function is intended to prevent the form from being submitted if the name field in the form is empty. What will the validate() function look like?
a. <script
type="text/javascript">
function Validate()
{
if(document.forms[0].name.value == "")
return true;
else
return false;}
</script>
function Validate()
{
if(document.forms[0].name.value == "")
return true;
else
return false;}
</script>
b. <script
type="text/javascript">
function Validate()
{
if(document.forms[0].name.value == "")
return false;
else
return true;
}
</script>
function Validate()
{
if(document.forms[0].name.value == "")
return false;
else
return true;
}
</script>
c. <script
type="text/javascript">
function Validate()
{
if(document.forms[0].name== "")
return false;
else
return true;
}
</script>
function Validate()
{
if(document.forms[0].name== "")
return false;
else
return true;
}
</script>
d. <script
type="text/javascript">
function Validate()
{
if(document.forms[0].name == "")
return true;
else
return false;
}
</script>
function Validate()
{
if(document.forms[0].name == "")
return true;
else
return false;
}
</script>
Which of the
following is the correct way to create an XML object in E4X?
a. var languages = new
XML('<languages
type="dynamic"><lang>JavaScript</lang><lang>Python</lang></languages>');
b. var languages XML = new
XML('<languages
type="dynamic"><lang>JavaScript</lang><lang>Python</lang></languages>');
c. var languages =
<languages type="dynamic">
<lang>JavaScript</lang>
<lang>Python</lang>
</languages>;
<lang>JavaScript</lang>
<lang>Python</lang>
</languages>;
d. All of the above are
correct.
e. a and c
f. b and c
What does the
following JavaScript code do? <head id="Head1"
runat="server">
<title></title>
<script type="text/javascript">
function validate() {
var chk = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
var ok = "yes";
var temp;
var field1 = document.getElementById("t1");
var field = field1.value.substring(field1.value.length - 1, field1.value.length);
if (chk.indexOf(field) == "-1") {
alert("error");
field1.value = (field1.value).slice(0, field1.value.length - 1);
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="text" id="t1" onkeyup="validate()" onkeypress ="validate()"/>
</form>
</body>
<script type="text/javascript">
function validate() {
var chk = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
var ok = "yes";
var temp;
var field1 = document.getElementById("t1");
var field = field1.value.substring(field1.value.length - 1, field1.value.length);
if (chk.indexOf(field) == "-1") {
alert("error");
field1.value = (field1.value).slice(0, field1.value.length - 1);
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="text" id="t1" onkeyup="validate()" onkeypress ="validate()"/>
</form>
</body>
a. The code will cause an
error alert to be displayed if a non alphabet character is entered.
b. The code will cause an
error alert to be displayed if ALPHABET character is entered.
c. The code will cause NO
error alert to be displayed if a numeric character is entered.
d. The code will cause NO
error alert to be displayed if a NON ALPHABET character is entered.
Answer of the last question is:
ReplyDeletea. The code will cause an error alert to be displayed if a non alphabet character is entered.
Apart from that most of the answers are correct...
I gave exactly same answer as you and i got 3.4 out of 5
ReplyDeletesame with me :P above average but its was very helpfulll
ReplyDeleteGot 70/100 only
ReplyDeleteWhich of the following Array methods in JavaScript runs a function on every item in the Array and collects the result from previous calls, but in reverse?
ReplyDeleteRight answer is reduceRight