Help | Site Map

Forums
- Programming Languages
  
  C / C++ Java .NET Visual Basic Python
- Web Development
  
  PHP Ruby / Rails Perl ASP Coldfusion Javascript / Ajax Flash / Actionscript XML HTML / CSS
- Database
  
  MySQL Oracle SQL Server PostgreSQL Access DB2
- System Administration
  
  Apache IIS Networking Linux / Unix / BSD Windows
- More
  
  Software Development Mobile Development Misc Questions
Howtos
- Browse all Howtos and articles here
Jobs
- Browse All Jobs
- Post Job Listing

Bytes > Forums - Questions and Answers > PHP Forum

Adding in php question

Question posted by: TheServant (Needs Regular Fix) on May 18th, 2008 05:25 AM

I have the following code which is part of a for loop. There are 2 arrays previously defined ($var, $bar):

Code: ( text )

echo ( "<tr><td><input name=\"".$var[$i]."_guild_upgrade\" type=\"submit\" value=\"Level ".++$bar[$i]."\" /></td></tr>" ) ;

That works 100%. However that is not what I tired first. I was tring to do this:

Code: ( text )

echo ( "<tr><td><input name=\"".$var[$i]."_guild_upgrade\" type=\"submit\" value=\"Level ".$bar[$i]+1."\" /></td></tr>" ) ;

This was coming up with a parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING?
Does anyone know why I can't use +1 instead of ++?

Would you like to answer this question?
Sign up for a free account, or Login (if you're already a member).

hsriat

Expert

1,427 Posts

May 18th, 2008
06:49 AM
#2

Re: Adding in php question

Enclose the adding thing in brackets.

($bar[$i]+1)

TheServant

Needs Regular Fix

462 Posts

May 18th, 2008
11:24 AM
#3

Re: Adding in php question

That's it! Thanks for that. I will continue using the ++ though!

hsriat

Expert

1,427 Posts

May 18th, 2008
11:46 AM
#4

Re: Adding in php question

Quote:

Originally Posted by TheServant

That's it! Thanks for that. I will continue using the ++ though!

Yeh, that's better to use ++ instead of doing increment separately.

Atli

Moderator

1,917 Posts

May 18th, 2008
02:42 PM
#5

Re: Adding in php question

It should be noted that by using ++ instead of +1 you are in fact changing the value of your array element.

Consider this:

Code: ( text )

$value = 1;
echo "Value + 1 = ". ++$value ."<br />";
echo $value; # Prints 2

Code: ( text )

$value = 1;
echo "Value + 1 = ". ($value + 1) ."<br />";
echo $value; # Prints 1

markusn00b

Expert

1,812 Posts

May 18th, 2008
04:32 PM
#6

Re: Adding in php question

Quote:

Originally Posted by Atli

It should be noted that by using ++ instead of +1 you are in fact changing the value of your array element.

Consider this:

Code: ( text )

$value = 1;
echo "Value + 1 = ". ++$value ."<br />";
echo $value; # Prints 2

Code: ( text )

$value = 1;
echo "Value + 1 = ". ($value + 1) ."<br />";
echo $value; # Prints 1

So $value will remain at 2.

Suarve.

Atli

Moderator

1,917 Posts

May 18th, 2008
05:21 PM
#7

Re: Adding in php question

Quote:

Originally Posted by markusn00b

So $value will remain at 2.

Suarve.

Yes, but if you are only trying to print the value + 1, incrementing it like this may cause problems.

For example, if your trying to print all elements of an array:

Code: ( text )

$someArray = array(1, 2, 4, 8, 16, 32, 64);
for($i = 0; $i < count($someArray); $i++) {
echo "Element ". ++$i ." = ". $someArray[$i] ."<br />";
}

This will skip every other element in the array and cause an undefined index error on the last loop.

You would either have to skip the incrementation in the for loop or just do ($i + 1).

TheServant

Needs Regular Fix

462 Posts

May 18th, 2008
10:03 PM
#8

Re: Adding in php question

Hmm, that's good to know, it works in my case but I will have to keep that in mind!

Not the answer you were looking for? Post your question . . .
174,849 Experts ready to help you find a solution.
Sign up for a free account, or Login (if you're already a member).

Top PHP Forum Contributors