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phparrayssyntaxnotationoperands

Single arrow vs double arrow mix and match

I frequently see $var->another_var, or $somevar=>yet_another, or even $third_var->another=>$fourth_var in various snippets of code.

Is there some super amazing info-graphic somewhere that clearly explains the various usages and what they mean, specifically within a PHP context?

(In my case, using Drupal, which uses LOTS of arrays, but probably useful in lots of other CMSs / frameworks.)

EDIT: I have since been informed about a catch-all page that has a very useful, encyclopedic list of various symbols and syntaxes. However, I believe one section NOT covered there is the mix-and-match combo of $var->element=>$anothervar.

Solution

    • $var->another_var is "property another_var of object referenced by $var".

    • $somevar=>yet_another is used in array definitions, like this: $arr = array($somevar => yet_another). It would define an associative property with key equal to the value of variable $somevar, and value equal to the constant yet_another.

    • $third_var->another=>$fourth_var can be rewritten so it becomes more clear: 

      array(  /*key=*/ ($third_var->another)  =>  /*value=*/ $fourth_var  )`