这是我的代码,有开关语句工作良好,但如果用户输入大于3或空白文本,那么它应该留在第一个子例程,我怎么能做到这一点在perl
use strict;
use warnings;
use Switch;
my $input = "Enter the number:";
sub input(){
print "Choose You Input Method"."n";
print "1.UPC"."n";
print "2.URL"."n";
print "3.Elastic Search"."n";
print $input;
$input = <>;
chomp($input);
switch($input){
case 1 {print "UPC"."n"}
case 2 {print "URL"."n"}
case 3 {print "Elastic Search"."n"}
else {print "Enter the correct value"."n"}
}
}
input();
my $pinput = "Enter the number:";
sub pinput(){
print "Choose Your Process Method"."n";
print "1.API"."n";
print "2.Mongo"."n";
print $pinput;
$pinput = <>;
chomp($pinput);
switch($pinput){
case 1 {print "API"."n"}
case 2 {print "MONGO"."n"}
else {print "Enter the correct value"."n"}
}
}
pinput();
如果用户输入4或空白数据,它不应该传递给另一个子例程,它应该留在同一个子例程上,我怎么能做到这一点?
用redo
:
#!/usr/bin/perl
use warnings;
use strict;
use Switch::Plain;
PROMPT: {
chomp(my $input = <>);
nswitch ($input) {
case 1 : { print "UPCn" }
case 2 : { print "URLn" }
case 3 : { print "Elastic Searchn" }
default : { print "Enter the correct valuen" ; redo PROMPT }
}
}
我使用Switch::Plain而不是Switch,因为它更安全(它不使用源过滤器)并且对您的情况足够。
perlfaq7 - How do I create a switch or case statement?
从5.10开始使用内置函数
use 5.010;
use strict;
use warnings;
PROMPT: {
chomp(my $input = <>);
given ( $input ) {
when( '1' ) { say "UPC" }
when( '2' ) { say "URL" }
when( '3' ) { say "Elastic Search" }
default { print "Enter the correct value"; redo PROMPT }
};
}