What does a . (dot) do in PHP?

下面的命令在PHP中做了什么？

. $string   // ($string is something which i declared in the program)

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On its own, that does nothing at all (it's not valid syntax). However, if you have something like this:

<?php

$string1 = "Hello ";
$string2 = "world!";
$string = $string1 . $string2;

echo $string;

?>

You will see Hello world! . The . is the string concatenation operator.

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Taken alone, this is a syntax error. The dot . is the concatenation operator that converts its arguments to strings and concatenates them. For example,

<?php
$string = "x";
$s = 42 . $string;
// $s is now "42x"

By the way, w3schools is a notoriously inaccurate source.

---

Your statement would throw back an error.

The "dot" is a string concatenator. That is, it helps you to combine strings together into another string.

Example. $full = $part1 . $part2;

Concerning getting started: That's a difficult question. PHP.NET will be your functional looking site. Google-ing just about anything on PHP will direct you there. I'd look at getting a localhost setup of PHP/MySQL/Apache. If you're on a Windows machine, you can get a WAMP server setup.

http://www.wampserver.com/en/

This will drastically speed up your development and testing time. Don't try to FTP everything up to a Web server, as this approach will waste away 10-15% of your working time. Work smart - work local.

Find an existing project (Open Source) with a great community and just try to start something. For example, I recently created DogFriendlyOlrando.com based on WordPress. I was curious as to the abilities of WordPress. It was a fun little project and gave me a good understanding of WordPress' capabilities. You'll learn the most from just diving in and doing. Good luck!

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