perl 期末考试题

PERL复习题一、选择题B1. What is the simplest type of data that Perl can work with?A elementB scalarC vectorD component2. Which operator can be used to take the bottom item from an array?A popB pushC pullD plant3. Which operator is used to arrange items in character order?A ascendB sortC arrangeD descend4. Rather than using print, what is often used in Perl when formatting is important?A printfB formatC alignD show5. Which modifier can be used when matching in Perl to ignore case?A sB vC iD c6. Which operator can be used to break up a string into more than one part based upon a separator?A chopB splitC divideD parse7. What option do you use when starting Perl to tell it to run in warning mode? __________ (Fill in the blank.)8. Which control structure can be used to execute only a condition is false?A untilB unlessC whileD without9. Which of the following commands should be used to open a filehandle named KAREN to an existing file named sw?A open KAREN “>sw”;B open KAREN, “>sw”;C open “sw” KAREN;D open “>sw”, KAREN;10. Within Perl, which operator is used to change the working directory?A cdB chdirC pwdD wd11. Which operator can be used to access the first item in an array?A shiftB startC right$D left$12. Within a loop, which operator immediately ends execution of the loop?A nextB lastC redoD leave13. Which function can be used to make sure your program exits with a nonzero status even if there a standard error?A hashB noexitC nozeroD die14. Which of the following operators work most like simple searching/pattern matching?A /fB /gC s///D m//15. Which keyword is used in Perl to define a subroutine?A branchB subC splitD make16. You want to close the directory handle EV AN. Which of the following should you use to accomplish this?A close EV AN;B closedir EV AN;C close_directory EVAN;D none of the above17. Which of the following lines of code accomplishes the same thing as $price = $price + 9;?A $price +9;B $price =+9;C $price +=9;D 9 + $price18. What value do variables have before they are first assigned?B nullC 0D nil19. Which Perl function can be used to launch a child process to run a program?A splitB spinC forkD system20. Which Perl function can be used to identify the first found occurrence of a substring?A findB indexC locateD allocate21. Which control structure can be used to loop as long as a conditional expression returns true?A untilB unlessC whileD without22. Which operator can be used to create private variables within a subroutine?A nativeB limitedC myD regional23. Which of the following operators is used to return a value in a subroutine?A returnB sendC giveD show24. Your script has just read in a variable from the keyboard and you want to strip that variable ofthe newline character that came in. What operator should you use to perform this operation?A tidyB trimC chompD slim25. What is the default sort order in Perl?A alphabeticB numericC ASCIID none of the above26. Within a loop, which operator jumps to the end of the loop but does not exit the loop?A nextB lastC redo27. Which of the following should be used to print values in an array that do not contain newlines and add them to the end of each entry?A print @array;B print @array\n;C print “@array\n”;D print “$@array \\”;28. Which string comparison operator would be equivalent to the numeric > operator?A neB eqC geD gt29. Which function can be thought of as the opposite of split?A linkB joinC uniteD bond30. Which operator can be used to add an item to the bottom of an array?A popB pushC pullD plant31. Which of the following mathematical operations has the highest precedence in Perl?A **B ++C +D -32. 以下哪一个字符串直接量的定义方式是错误的（）（1）'thank you'（2）" "（3）"a "friend" of yours"（4）"a \"friend\" of yours"33. 以下哪一条语句是错误的（）（1）$_= 'hello world';（2）$a='hello world';（3）my $b,$a='hello world';（4）my ($a,$b)=(0,'hello world');34. 要使下面的程序正常运行，while 后的表达式应选（）。

$a=0;$b=55;while (表达式){$a+=2; }print "$a\n";（1）$a = $b（2）$a*$a <= $b（3）$a != $b（4）$b == 035. 在Perl 及其它程序设计语言中，数据是由（）。

（1）变量来表示的。

（2）运算符来表示的。

（3）变量的值来表示的。

（4）运算符的值来表示的。

36. @array是一个数组变量，语句print @array;输出的是：（）（1）数组的各个元素。

（2）数组的大小。

（3）数组的第一个元素。

（4）什么都不输出。

37. 语句$a = @array;执行后，变量$a的值是（）。

（1）数组@array 的第一个元素的值。

（2）数组@array 的大小。

（3）此语句语法是错的。

（4）未定义。

38. 以下是用递归子程序求45 的3 次方，if后的表达式应该是（）sub power{($m , $n)=@_;$n>=1 || die 'error!';return($m) if(表达式);return($m*power($m , $n-1));}print power(45,3);（1）$n == 1（2）$n < 0（3）$n> = 1（4）$n != 039. 如要在子程序中接受两个作为参数的数组，则（）（1）子程序用一个二维数组作形参。