php syntax enclosing brackets

Question

Simple question:
I've been exploring open source code and saw the following statement:

$this->{$worker}

What is the meaning of enclosing brackets around, and what is the difference between this and:

$this->worker

`$worker = 'somevar';` so `$this->{$worker} == $this->somevar` — AbraCadaver, Feb 18 '15 at 13:50
possible duplicate of [Get PHP class property by string](http://stackoverflow.com/questions/804850/get-php-class-property-by-string) — Rizier123, Feb 18 '15 at 13:51

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

Curly braces are used for string or variable interpolation in PHP.

Something like

$worker = 'foo';
$this->{$worker} = 'bar';

that means

$this->foo = 'bar';

When is useful

class RandomName
{
    protected $foo;
    protected $bar;
    protected $foo_bar;

    $properties_array = array('foo', 'bar', 'foo_bar');
    if (in_array($property, $properties_array)) {
        $this->{$property} = //some value
    }
}

score 1 · Answer 2 · answered Feb 18 '15 at 13:51

1

The first one actually uses the value of the variable $worker, while the latter uses the Expression / word worker to target the object property.

answered Feb 18 '15 at 13:51

Tacticus

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score 0 · Answer 3 · answered Feb 18 '15 at 13:51

0

The first example is using a variable as the attribute name. The second example is using a non-variable name for an attribute on your class.

answered Feb 18 '15 at 13:51

Dragony

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php syntax enclosing brackets

3 Answers3

When is useful