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" IF " Statments ..

Always IN Chaos
Novice

Nov 20, 2003, 7:54 PM

Post #1 of 8 (2843 views)

" IF " Statments ..	Can't Post

What's the order ??

Code

While  
{ 
 
 
If  
{ 
} 
 
else  
{ 
} 
 
if 
{ 
} 
 
elsif 
{ 
} 
 
 
}

davorg
Thaumaturge / Moderator

Nov 21, 2003, 1:55 AM

Post #2 of 8 (2839 views)

Re: [Always IN Chaos] " IF " Statments .. [In reply to]	Can't Post

Not sure what you're asking. Please rephrase your question.

--
Dave Cross, Perl Hacker, Trainer and Writer
http://www.dave.org.uk/
Get more help at Perl Monks

Always IN Chaos
Novice

Nov 21, 2003, 2:36 AM

Post #3 of 8 (2837 views)

Re: [davorg] " IF " Statments .. [In reply to]	Can't Post

is the "code" above the correct format for doing While "blocks" or is there a better way?

davorg
Thaumaturge / Moderator

Nov 21, 2003, 5:23 AM

Post #4 of 8 (2836 views)

Re: [Always IN Chaos] " IF " Statments .. [In reply to]	Can't Post

The syntax for a while loop is

Code

while (COND) BLOCK

Where "COND" is any logical condition and "BLOCK" is a block of code that is executed as long as COND is true. Note that in Perl a block of code is always delimited with { and } so an example while loop might look like this

Code

$x = 10; 
while ($x) { 
  print "$x\n"; 
  --$x; 
}

Does that help? I'm still not sure I understand your question.

--
Dave Cross, Perl Hacker, Trainer and Writer
http://www.dave.org.uk/
Get more help at Perl Monks

madhu_p
Novice

Nov 29, 2003, 10:34 AM

Post #5 of 8 (2823 views)

Re: [Always IN Chaos] " IF " Statments .. [In reply to]	Can't Post

try this# I think u should use 'else' after 'elsif'While (cond)
{

If (cond)
{
}

else
{
}

if (cond)
{
}

elsif (cond)
{
}
else(cond) # I think u should use 'else' after 'elsif'.{}
}hope this could help u Smile

madhu
Kaiserslautern,Germany

davorg
Thaumaturge / Moderator

Nov 30, 2003, 1:17 PM

Post #6 of 8 (2817 views)

Re: [madhu_p] " IF " Statments .. [In reply to]	Can't Post

In Reply To

try this# I think u should use 'else' after 'elsif'While (cond)
{

If (cond)
{
}

else
{
}

if (cond)
{
}

elsif (cond)
{
}
else(cond) # I think u should use 'else' after 'elsif'.{}
}

You don't need to have an 'else' clause after an 'elsif' clause unless your logic requires it.

An 'else' clause _never_ has a condition block.

--
Dave Cross, Perl Hacker, Trainer and Writer
http://www.dave.org.uk/
Get more help at Perl Monks

madhu_p
Novice

Dec 1, 2003, 4:01 AM

Post #7 of 8 (2814 views)

Re: [davorg] " IF " Statments .. [In reply to]	Can't Post

Iam sorry ,iam wrong 'else 'will not have condition but I think 'else' will follow 'elsif'(ref:programming perl O'reilly : page no:94)

so it will be

'elsif'While (cond)
{

If (cond)
{
}

else
{
}

if (cond)
{
}

elsif (cond)
{
}
else # I think u should use 'else' after 'elsif'.

{

}

}
Kaiserslautern,Germany

davorg
Thaumaturge / Moderator

Dec 1, 2003, 7:39 AM

Post #8 of 8 (2811 views)

Re: [madhu_p] " IF " Statments .. [In reply to]	Can't Post

In Reply To

Iam sorry ,iam wrong 'else 'will not have condition but I think 'else' will follow 'elsif'(ref:programming perl O'reilly : page no:94)

Please include the edition number when referencing pages in books as they can change between editions. Page 94 of the most recent (3rd) edition has nothing to say about if, elsif or else. But on page 113 it has the following examples of compound logical statements:

Code

if (EXPR) BLOCK 
if (EXPR) BLOCK else BLOCK 
if (EXPR) BLOCK elsif (EXPR) BLOCK ... else BLOCK

Which does, I confess, imply that an "elsif" block must have a following "else" block, but it's not true. As simple experimentation would have shown. The "else" block is _always_ optional.

I'll submit a patch to the documentation.

--
Dave Cross, Perl Hacker, Trainer and Writer
http://www.dave.org.uk/
Get more help at Perl Monks

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