PHP & MySQL® Web Development All-in-One Desk Reference for Dummies®

1.5. Displaying Content in a Web Page

You display content on your Web page with echo statements. An echo statement produces output, which is sent to the user's browser. The browser handles the output as HTML.

The general format of an echo statement is

echo outputitem,outputitem,outputitem,...

where the following rules apply:

• An outputitem can be a number, a string, or a variable (using variables is discussed in the section "Using PHP Variables," later in this chapter. A string must be enclosed in quotes.

• List as many outputitems as you need, separated by commas.

Table 1-1 shows some echo statements and their output.

Table 1.1. echo Statements

echo Statement	Output
echo "Hello";	Hello
echo 123;	123
echo "Hello","World!";	HelloWorld!
echo Hello World!;	Not valid; results in an error message
echo "Hello World!";	Hello World!
echo 'Hello World!';	Hello World!

echo statements output a line of text that's sent to a browser. The browser considers the text to be HTML and handles it that way. Therefore, you need to make sure that your output is valid HTML code that describes the Web page that you want the user to see.

When you want to display a Web page (or part of a Web page) by using PHP, you need to consider three stages in producing the Web page:

• The PHP script: PHP echo statements that you write.

• The HTML source code: The source code for the Web page that you see when you choose ViewSource in your ...