如何检查函数是否有值[重复]

Question

This question already has an answer here:

• How do you create optional arguments in php? 6 answers

I am not sure if the title is correct, my problem is that I have a class and functions inside it, I would like to check if the value for the function is set and if not set other value

class some_class
{
    private $width;

    function width( $value )
    {
        // Set another default value if this is not set
        $this->width = $value;
    }
}

$v = new some_class();


// Set the value here but if I choose to leave this out I want a default value
$v->width( 150 );

</div>

Answer 1

Try this

class some_class
{
    private $width;
    function width( $value=500 )  //Give default value here
    {
        $this->width = $value; 
    }
}

Check Manual for default value.