PHP introductory tutorial: basic syntax that beginners must master

PHP is widely used in Web development and is a server-side scripting language. Before learning PHP, we need to have basic knowledge of HTML and CSS. The following will introduce the basic syntax of PHP that beginners must master.

1. Variables

Variables are defined and assigned using the $ symbol in PHP, such as $variable="hello world";. Variable names must start with the $ symbol and can only contain letters, numbers, and underscores. Variables in PHP have the characteristics of dynamic types and can store data types such as numbers, strings, and arrays.

2. Operators

PHP supports common operators, including addition, subtraction, multiplication, division, remainder, increment and decrement, etc. It should be noted that when using the increment and decrement operators, the difference between the prefix and suffix will lead to different results. For example: $i=5;$j= $i; // $j=6, $i=6;$ k=$i; // $k=6,$i=7;

3. Conditional statements

Conditional statements are used to execute different code blocks based on different conditions. PHP supports conditional statements such as if statements and switch statements. The if statement is used to determine whether a condition is true and execute the corresponding statement block. The switch statement is used to determine which code block to execute based on the value of an expression.

4. Loop statement

The loop statement allows the program to repeatedly execute a block of code until a condition is not true. PHP supports loop statements such as for loop, while loop, do...while loop, etc. The for loop is more flexible and can set the starting value, end value and step size of the loop. The while loop loops through a block of code until a condition is not true. The do...while loop is similar to the while loop, but it executes the code block once and then checks whether the condition is true.

5. Array

Array is a very important data type in PHP, which can store a set of data. PHP supports two types of indexed arrays and associative arrays. Indexed arrays access array elements through numeric indexes, and associative arrays access array elements through string indexes.

6. Function

A function is a collection of code that can be used repeatedly. There are many built-in functions in PHP, such as string processing functions, date functions, etc. We can also customize functions to meet the needs of the program. To define a function, use the keyword function, and to call a function, just use the function name.

7. File operation

In web development, it is often necessary to read files or write data to files. PHP provides a wealth of file operation functions, such as fopen, fclose, fread, fwrite, etc. Through file operation functions, file reading and writing operations can be completed conveniently.

Summary:

This article introduces the basic syntax of PHP that beginners must master, including variables, operators, conditional statements, loop statements, arrays, functions and file operations. Of course, to truly master the PHP language requires continuous practice and learning. At the same time, it should be noted that in order to write standardized code, you need to pay attention to issues such as code indentation, comments, and naming conventions. Only by writing standardized code can the readability and maintainability of the code be improved.

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