If GET variable empty then default value

[mastubbs]

Hi All,

 

I have a script that relies on a numeric variable from GET. I am trying to figure out how to have a 'default' value if no GET value is passed in the url.

 

I have been trying to get it to work with if() but no joy:

$par2 = $_GET['par1']; 

if(empty($par2))
{ $par = 4; 
} $par = $par2;

So if a value for 'par1' is passed in the url then $par will be whatever that value is. However if no value is passed then the default value for $par should be 4. Unfortunately that code doesn't seem to work. If i pass no 'par1' value in the url i jest get a php error. Any tips on where im going wrong here would be much appreciated.

 

Thanks in advance for any help,

 

Matt

[thara]

I think you have missed else part from your 'if' condition.

 

try this. 

if(empty($_GET['par1'])) {
    $par = 4;    
} else {
    $par = $_GET['par1'];    
}

In this case you can also use php ternary operator:

 

your code should be something similar to this using Ternary Operator

$par = (empty($_GET['par1'])) ? 4 : $_GET['par1'];

Edited July 7, 2013 by thara

[Barand]

Better to check if it is set also

$par = (isset($_GET['par1']) && !empty($_GET['par1']) ) ? $_GET['par1'] : 4;

[litebearer]

Being that the OP is looking for the variable to be numeric. wouldn't it be prudent to incorporate  a check to ascertain it is numeric?

[mastubbs]

 

I think you have missed else part from your 'if' condition.

 

try this. 

if(empty($_GET['par1'])) {
    $par = 4;    
} else {
    $par = $_GET['par1'];    
}

In this case you can also use php ternary operator:

 

your code should be something similar to this using Ternary Operator

$par = (empty($_GET['par1'])) ? 4 : $_GET['par1'];

 

Whops yep i forgot the 'else', thanks.

 

Thanks also for introduction to ternary operator.

 

Matt

[mastubbs]

Ah... i have noticed a problem here. Sometimes the value of 'par1' will be 0.  The problem with the methods above is that they seem to assume that par1 = 0 is the same as empty. Is there a way to get it to recognise 0 as a number, but still default to '4' if empty ?

 

Thanks all for the help,

 

Matt

[AbraCadaver]

$par = (isset($_GET['par1']) && is_numeric($_GET['par1'])) ? $_GET['par1'] : 4;

//or

$par = (isset($_GET['par1']) && $_GET['par1'] != '') ? $_GET['par1'] : 4;

 

[mastubbs]

$par = (isset($_GET['par1']) && is_numeric($_GET['par1'])) ? $_GET['par1'] : 4;
//or
$par = (isset($_GET['par1']) && $_GET['par1'] != '') ? $_GET['par1'] : 4;

 

Perfect, thanks.