I have been editing an existing php script and have come across a function as so
function functionName($var1 = null, $var2 = null, $var3 = null)
I'm not sure why you would declare a var as null in this way. I have tried looking for an answer online but google pulls up anything but this example.
Any help would be greatly appreciated.
These are default values: you don't have to specify them when you call the function. When you omit them, the default value will be used.
See example #3 on this manual page. From there:
<?php
function makecoffee($type = "cappuccino")
{
return "Making a cup of $type.\n";
}
echo makecoffee();
echo makecoffee(null);
echo makecoffee("espresso");
?>
will output
Making a cup of cappuccino.
Making a cup of .
Making a cup of espresso.
The function is defined with NULL as the identifier of the default variable. See example #3 on the documentation for functions in the PHP manual.
The argument $var1 is optional and is not required. If specified, the given value will be used. If not, the value specified as the default value will be used.
Another example:
function sayHello($person = 'stranger') {
return "Hello, $person";
}
echo sayHello('Rob');
echo sayHello('Tom');
echo sayHello();
It will output:
Hello, Rob
Hello, Tom
Hello, stranger
Refer to the PHP manual for more information.
Hope this helps!
It's just a default value : when you call the function, if you don't set a value to $var it will take the default one.
For example :
function foo($bar = 'default')
{
return $bar;
}
echo foo(); // Will display "default"
echo foo('Hello world!'); // Will display "Hello world!"
when you put in a value into a parameter like this mean, if you don't pass a nothing 'lol'(or other value) will be default.
function foo($param1 = 'lol'){
echo $param1;
}
foo(); //'lol';
foo('new foo'); // new foo
