Getting Started with PHP: Basic PHP Syntax

PHP is a server-side scripting language that is used to develop dynamic websites, web applications, and web programs. PHP has a wide range of applications, and both beginners and experienced developers can benefit from it.

This article will provide you with an introductory guide to the basic syntax of PHP. If you want to learn PHP programming and build a solid foundation from scratch, you've come to the right place.

1. The basic structure of PHP

A PHP program contains the following three parts:

//PHP code
?>

The on both sides of the code mark the beginning and end of PHP. All PHP code is written between these two identifiers.

2. Variables

In PHP, variables are used to store data. Variable names start with $, followed by the variable name, such as $variablename. The assignment sign (=) is used to assign a value to a variable.

$greeting = "Hello, World!";
?>

The above code creates a variable named $greeting and sets "Hello, World!" is assigned to it.

3. Data types

PHP supports the following data types:

• String - a string of characters.
• Integer (Integer) - a number without decimals.
• Boolean value (Boolean) - a value representing true or false.
• Float - numbers with decimals.
• Array (Array) - used to store multiple values.
• Object (Object) - stores information about objects.
• NULL - represents a null value.

4. Operators

PHP contains a variety of operators, including arithmetic operators, comparison operators and logical operators. Here are some typical examples of operators:

Arithmetic operators:

$x = 10;
$y = 5;
echo $ x $y; // Output 15
echo $x - $y; // Output 5
echo $x * $y; // Output 50
echo $x / $y; // Output 2
?>

Comparison operator:

$x = 10;
$y = 5;
var_dump($x = = $y); // Output bool(false)
var_dump($x != $y); // Output bool(true)
var_dump($x > $y); // Output bool( true)
var_dump($x var_dump($x >= $y); // Output bool(true)
var_dump($x ?>

Logical operator:

$x = true;
$y = false;
var_dump($x && $y); // Output bool(false)
var_dump($x || $y); // Output bool(true)
var_dump( !$x); // Output bool(false)
?>

5. Control structure

Control structure is one of the basic concepts in programming. They Control the execution flow of the program. PHP supports a variety of control structures, including conditional statements, loop statements, and jump statements. Here are some common examples of control structures:

Conditional statement:

if statement:

$hour = date('H');
if ($hour

echo "Good morning!";

} elseif ($hour

echo "Good afternoon!";

} else {

echo "Good evening!";

}
?>

switch statement:

$day = date("D");
switch ($day) {

case "Mon":
    echo "Today is Monday!";
    break;
case "Tue":
    echo "Today is Tuesday!";
    break;
case "Wed":
    echo "Today is Wednesday!";
    break;
case "Thu":
    echo "Today is Thursday!";
    break;
case "Fri":
    echo "Today is Friday!";
    break;
case "Sat":
    echo "Today is Saturday!";
    break;
case "Sun":
    echo "Today is Sunday!";
    break;
default:
    echo "Invalid day!";

}
?>

Loop statement:

for loop:

for ($x = 0; $x

echo "The number is: $x <br>";

}
?>

while loop:

$x = 1;
while ($x

echo "The number is: $x <br>";
$x++;

}
?>

do...while loop:

$x = 1;
do {

echo "The number is: $x <br>";
$x++;

} while ($x ?>

6. function

A function is a reusable block of code that accepts some parameters and performs some operations. PHP has an extensive library of built-in functions, and developers can also create their own custom functions.

The following is an example of a custom function:

function helloWorld($name) {

echo "Hello, $name!";

}
helloWorld("John "); // Output Hello, John!
?>

7. Conclusion

This PHP introductory guide introduces the basic syntax of PHP. To become a skilled PHP developer, you must learn to use these basic syntaxes. We hope this article helped you get started writing PHP applications and websites.

The above is the detailed content of Getting Started with PHP: Basic PHP Syntax. For more information, please follow other related articles on the PHP Chinese website!