CODEWITHSUNDEEP
perl
kurotsuki
kurotsuki

Reputation: 4777

While loop with an "OR" condition

Below is a code snippet that asks for user input, and if the input is not either "csv" or "newline", the while loop is called.

For line 5, what is the correct syntax for the while loop where it attempts to match $format to either "csv" or "newline"? Currently it is only seems to be matching "csv".

1 # Request output format
2 print "Format of email addresses required (csv|newline): ";
3 $format = <>;
4 chop($format);
5 while ($format ne ("csv"||"newline")) {
6   print "Invalid format. Enter in csv or newline: ";
7   $format = <>;
8   chop($format);
9 }

Upvotes: 2

Views: 8807

Answers (5)

Sid Malani
Sid Malani

Reputation: 2116

($format ne "csv" && $format ne "newline")...

Upvotes: 0

avpaderno
avpaderno

Reputation: 29679

You should use while (($format ne "csv") && ($format ne "newline")) { }.

In your code, the result of "csv"||"newline" is "cvs"; your code is then equivalent to while ($format ne "csv") { }.

Upvotes: 1

rob mayoff
rob mayoff

Reputation: 385580

while ($format ne 'csv' && $format ne 'newline') {
    ...
}

or

while ($format !~ /^(csv|newline)$/) {
    ...
}

Upvotes: 7

Richard Sim&#245;es
Richard Sim&#245;es

Reputation: 12801

If using Perl >= v5.10, the closest working example to what you tried is:

while ( not $format ~~ ["csv", "newline"] ) {

Otherwise, both of rob mayoff's solutions will work just fine.

Upvotes: 8

mmtauqir
mmtauqir

Reputation: 9309

while (($format ne "csv") && ($format ne "newline))

Since || is a short-circuiting operator, the expression ("csv" || "newline) returns "csv" because csv is doesn't evaluate to false, so its returned first. If it was ("newline" || "csv"), it would have returned newline (I believe).

Upvotes: 2

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