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Test your basic knowledge |
Perl Programming
Start Test
Study First
Subject
:
it-skills
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Stores information about the current users environment. You can print this from the command line using printenv
chomp(@string)
@arrayName size
delete($hashName{key})
%ENV hash array
2. Regular __________: * - 0 or more characters - + - 1 or more characters - ? - 0 or 1 characters
Expression Quantifiers
Scalar variables
$line=<FILEHANDLE>
foreach
3. $#arrayName returns the value of the ______ of the array (NOT the data stored in that array element)
execution block
arithmetic comparison operators
$line=<FILEHANDLE>
last index
4. Common ________: pop(@array) - push(@array, $new Value) - shift(@array) - unshift(@array, $newValue) - sort(@array) - reverse(@array)
array functions
system() function
each(%hash)
Hash variables
5. Adds a new element to end of the array with value $newValue
foreach
push(@array, $newValue)
Editing
lcfirst($string)
6. Returns the sub string starting at index $startindex and ending after $numchars chars in the string $string
delete($hashName{key})
FILEHANDLE
substr($string, $startindex, $numchars)
reverse(%hashName)
7. Explain how to read a line from a file handle
system commands
$line=<FILEHANDLE>
Assignment
print(FILEHANDLE "Data to outputn");
8. Assignment of a hash variable for a single hash element
Assignment
Variable context
string manipulation functions
$hashName{keyName}="Value to Add"
9. Returns a copy of the string with the first letter upper case
command substitution
ucfirst($string)
@arrayName size
Scalar variables
10. _________ @arrayName) returns the size of the array
each(%hash)
print(FILEHANDLE "Data to outputn");
access modes
scalar
11. To read an entire file into an array (one line per element)
Array variables
arithmetic comparison operators
@entireFile=<FILEHANDLE>
values(%hash)
12. The use of ______ in perl - Documenting code - Created by placing a "#" on a line. - are not multi-line
hash functions
exists($hashName{keyName})
use moduleName; Ex: use Roman;
comments
13. Removes the first element of the array shift
system() function
Scalar variables
%hashname = (key1=>"value1", key2=>"value2", key3=>"Value3")
(@array)
14. To write to a filehandle
@arrayName size
print(FILEHANDLE "Data to outputn");
ucfirst($string)
Assignment
15. To get rid of the ________ in $line you could now chomp() (Ex: chomp($line);)
newline
delete($hashName{key})
like functions
scalar
16. Reverses the elements of the array
size string comparison operators
@entireFile=<FILEHANDLE>
Editing
reverse(@array)
17. eq - ne - lt - le - gt - ge
Variable context
sort(@array)
Expression Quantifiers
size string comparison operators
18. The open() statement in perl: open(________, file_mode, "filename.txt")
FILEHANDLE
(@array)
keys(%hash)
$hashName{keyName}="Value to Add"
19. The three basic ________ of the open() function: > write - >> append - < read file
Expression Quantifiers
Scalar variables
access modes
last index
20. Assignment of hash variables in perl (when oringally defining the hash)
%hashname = (key1=>"value1", key2=>"value2", key3=>"Value3")
@entireFile=<FILEHANDLE>
keys(%hash)
length($string)
21. The variable that provides the last index of an array
Editing
$#arrayName
string manipulation functions
@entireFile=<FILEHANDLE>
22. Returns the length of the string including escape sequences
Special array
length($string)
chomp(@string)
scalar
23. _________ in perl - Singular variable - starts with "$" - Number or characer or string- Perl does automatic type conversion of these
arithmetic comparison operators
%hashname = (key1=>"value1", key2=>"value2", key3=>"Value3")
Scalar variables
each(%hash)
24. The __________ in perl: - uses grave marks `command args`- returns the output of the command to the variable you specify - if $output = `command arg` the output is stored all in one variable (all lines seperated by n) - if @output = `command arg` the
Assignment
command substitution
size string comparison operators
newline
25. Two ____________ in regular expressions: =~ Contains - !~ Does not contain
like functions
(@array)
$hashName{keyName}="Value to Add"
basic binding operators
26. Add a new element to the from of the array with the value $newwValue
chomp(@string)
unshift(@array, $newValue)
Expression character classes
exists($hashName{keyName})
27. Returns a two element ray of the next key value pair; resultArray[0] is the key resultArray[1] is the value
each(%hash)
Special array
lc($string)
Editing
28. Swap keys for values and values for keys. Will cause issues if there are multiple hash entries with the same value
arithmetic comparison operators
reverse(%hashName)
length($string)
newline
29. Common ___________: substr($string, $start, $numchars); - length($string) - lc($string) - uc($string) - chomp($string) - chomp(@string) - join(':", @string) - split(/\s/, $string) - lcfirst($string) - ucfirst($string)
Expression character classes
string manipulation functions
hash functions
join(':', @array)
30. Does the hash key with "keyName" exists
like functions
exists($hashName{keyName})
sort(@array)
uc($string)
31. Returns a copy of the string as all lower case
lc($string)
substr($string, $startindex, $numchars)
arithmetic comparison operators
comments
32. ________ in perl - A collection of data (static data or scalar variables or arrays or hashes can all be stored in an array element)
Assignment
@arrayName size
Array variables
Special array
33. The four types of loops in perl: while - until - for - ________
foreach
Special array
like functions
chomp($string)
34. Remove trailing newline from each element in the array
(@array)
chomp(@string)
join(':', @array)
use moduleName; Ex: use Roman;
35. Removes the last element from the array pop
keys(%hash)
(@array)
last index
lc($string)
36. The two primary methods of executing _______ in perl: - system("command args") - - `command args`
hash functions
system commands
@arrayName size
values(%hash)
37. Regular ____________: w - alphanumeric word including underscor - d - digits 0-9 - s any whitespace - . - any character
Assignment
Special array
Expression character classes
size string comparison operators
38. The _______ in perl: - used to execute an external command - will output results of command to terminal - returns the exit status of the program that ran - use this for commands that you dont care about SAVING the output to a variable
system() function
keys(%hash)
print(FILEHANDLE "Data to outputn");
last index
39. _________ in perl - An associative array
system() function
%ENV hash array
command substitution
Hash variables
40. A special system variable used to pass arguments to script
Expression character classes
@ARGV
substr($string, $startindex, $numchars)
push(@array, $newValue)
41. Arrays can be assigned or read in _________
@arrayName size
(@array)
scalar context (Ex: $myArray[4] = 2)
Assignment
42. Join the elements of the array seperating the elements with the ':' character
43. The use of "if" "if-else" and "if-elsif-else"
FILEHANDLE
basic binding operators
flow-control
Variable context
44. Returns a copy of the string with the first letter lower case
length($string)
keys(%hash)
lcfirst($string)
sort(@array)
45. scalar(@arrayName) returns the ______ of the array names
reverse(%hashName)
@arrayName size
lcfirst($string)
last index
46. Common ________: keys(%hash) - values(%hash) - each(%hash) - delete($hash{keyName}) - exists($hash{keyName}) - reverse(%hash)
hash functions
substr($string, $startindex, $numchars)
size string comparison operators
Expression character classes
47. The purpose of {} in an "if" statement: To Define the __________ of the if statement. Unlike C the {} braces ARE REQUIRED
split(/\s/, $string)
%hashname = (key1=>"value1", key2=>"value2", key3=>"Value3")
execution block
arithmetic comparison operators
48. Returns all of the values of the hash as an array
system() function
size string comparison operators
values(%hash)
%ENV hash array
49. Sort and array alphabetically
sort(@array)
Variable context
basic binding operators
$line=<FILEHANDLE>
50. In perl the _______ will recognize syntax errors and halt execution BEFORE it begins - and will output statements; it does not understand and the line which it encountered the error on
interpreter
@entireFile=<FILEHANDLE>
size string comparison operators
like functions