“Sometimes, it requires executing one or more statements based on a particular condition. This problem can be solved by using the “if” statement. It is a very useful statement for any programming language. The ways of using different types of “if” statements in the PERL script have ...
if (Expression) {Code Segment} else {Code Segment} if (Expression) {Code Segment} elsif (Expression) {Code Segment} else {Code Segment} # elsif 就是 else if # 如果指令(statement)只有一项,我们可以使用倒装句法,看起来比较简洁。 statement if (Expression); # unless 就是if not statement unless...
if (Expression) {Code Segment}elsif(Expression) {Code Segment} else {Code Segment} # elsif 就是 else if # 如果指令(statement)只有一項,我們可以使用倒裝句法,看起來比較簡潔。 statementif(Expression); # unless 就是if not statementunless(Expression); 例: print "HELLO!\n" if ($name eq "frien...
if 语句 当您需要检查语句的返回值时, if statement是显而易见的选择; 例如 - if(open(DATA, $file)) { ... } else { die "Error: Couldn't open the file - $!"; } 123456 这里变量$! 返回实际的错误消息。 或者,我们可以在有意义的情况下将陈述减少到一行; 例如 - open(DATA, $file) || ...
statement if (Expression); # unless 就是if not statement unless (Expression); 例: print "HELLO!\n" if ($name eq "friend"); $x-=10 if ($x == 100); 看吧! C 語言有的Perl大部分都有,學過 C 的人可以毫不費力的學會Perl。
if 语句 当您需要检查语句的返回值时, if statement是显而易见的选择; 例如 - if(open(DATA, $file)) { ... } else { die "Error: Couldn't open the file - $!"; } 123456 这里变量$! 返回实际的错误消息。 或者,我们可以在有意义的情况下将陈述减少到一行; 例如 - ...
举个例子，比如我们要匹配Http状态的话，没有模式匹配的，使用if/else的话，会写成下面这样：
Check current element matches the given element using the if conditional statement. prints a string to the console. Here is an example @numbers= (1, 2, 3,4,5,6);my$searchElement=1;for(@numbers) {if($_eq$searchElement) {print"exists";last;}} ...
Perl Statement Next Next if #!/usr/bin/perl -w use strict; print "Please enter some text:\n"; while (<STDIN>) { next if $_ eq "\n"; chomp; print "You entered: [$_]\n"; } Related examples in the same category1. Using the next statement in a foreach structure. 2. ...
If you need both"next"and"last", you have to do both and also use a loop label: LOOP: { do {{ next if $x == $y; last LOOP if $x == $y**2; # do something here }} until $x++ > $z; } NOTE:The behaviour of a"my","state", or"our"modified with a statement modifier...