这在$ variable-> function（）中是什么意思（ - >）？

Hello guys I've looking on many php scripts and I saw something like this

$variable->function($var1, $var2, $var3)

So what does this -> exactly do ?

and thank you.

its a function call on an object

Object-Variable: $variable

Call: ->

Function: function(...)

It implies $variable is an object, and is calling the "function" method of the object assigned to $variable.

It calls a method on an object. But to understand what that means, you need to understand object-oriented programming in PHP. The manual is extremely good, read it here:

http://php.net/manual/en/language.oop5.php

The -> access a function within the $variable's class. So a $variable might be an instance of a class like,

$variable = new Person();
$variable->showFirstName();

and in class Person, there would be a function

function showFirstName() {
    echo $this->$first_name;
}

PHP Object Orientation Basics

A more generic info at Wikipedia: Object Oriented Programming

I don't think it is a good idea to give a direct answer, like the others already did but to give a link to the topic itself since without the background, most of the answers won't make much sense.