oDesk JavaScript 1.8 Test answer 2015
·
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>
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
