PHP Grammar Basics, front-end PHP Syntax _php tutorial

The front-end must learn PHP grammar basics, the front-end PHP syntax

Write it in front.

PHP is a powerful server-side scripting language for creating dynamic, interactive sites. PHP can contain text, HTML, CSS, and PHP code, executed on the server, and returned to the browser in plain text.

Code identification

PHP code begins with <?php, ends with?>, and can be placed anywhere in the document

<?php//?>

The PHP statement ends with a semicolon (;), and the close tag of the PHP code block automatically indicates the semicolon

<?phpecho "Hello world!";? >

Comments

PHP supports three types of annotations, including two single-line comments and one multiline comment

<?php//This is a single-line comment # This is also a single-line comment/* This is a multiline comment block which spans multiple lines */?>

Output

In PHP, there are two basic output methods: Echo and Print

Print can output only one string, and always returns 1

Echo is capable of outputting more than one string, and echo is slightly faster than print because it does not return any value

　　between Scripts, it's important to note that both Echo and print are language structures, with either echo or Echo (), or print or print (), and a minimum of one space between the echo or print keyword and the string

<?phpecho "
PHP is fun!
"; echo" Hello world!
"Echo" I ' m about to learn php!
"; echo" This "," string "," is "," made "," with multiple parameters. ";? ><?phpprint "
PHP is fun!
";p rint" Hello world!
";p rint" I ' m about to learn php!
";//The line went wrong because print can only output 1 strings of print" This "," string "," is "," made "," with multiple parameters. ";? >

evaluating expressions

Unlike HTML and CSS, you can write calculation expressions in PHP

<?php//36echo 12*3;? >

Uppercase and lowercase

In PHP, all user-defined functions, classes, and keywords are case insensitive, but all variables are case-insensitive

<?php//hello world! ECHO "Hello world!
";//hello World!echo" Hello world!
";//hello world! EcHo "Hello world!
";? >

　　Help the home friendship reminds everyone to pay attention to the point : . Number for string connection, in other programming languages, General + number

<?php$color= "Red";//my car is Redecho "My car is". $color. "
";//my house was echo" My house is ". $COLOR. "
";//my boat Isecho" My boat is ". $coLOR. "
";? >

The above content is a small series to share the front-end must learn PHP Grammar Foundation, I hope to help you, at the same time thank you all have been to help the home site support, at the same time I wish everyone happy New Year.

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