php interpratation of ':' and '?'

Question

I'm working on a wordpress widget that utilizes Johnathan Christopher's 'Widget Image Field' pluggin. I'm confused by this line of code.

$image_id = esc_attr( isset( $instance[$this->image_field] ) ? $instance[$this->image_field] : 0 );

What does the '?' and ':' do?

It's the _ternary operator_. Stack Overflow is not supposed to be a substitute for reading documentation. — Barmar, Jun 07 '13 at 01:21

score 0 · Accepted Answer · answered Jun 07 '13 at 01:22

0

It is the same that:

if(isset( $instance[$this->image_field]))
{
    $image_id =  $instance[$this->image_field];
}
else
{
     $image_id = 0;
}

This is the ternary operator. Here you can learn about.

answered Jun 07 '13 at 01:22

Rafael Azevedo

You should not ask such a question, and go to practice before asking such question on SO (which is not here for that) – MatRt Jun 07 '13 at 03:42

1 Answers1