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PHP Built-in Functions

Introduction

This tutorial will cover the built-in functions in PHP. Functions are reusable pieces of code that perform a specific task. PHP, like most programming languages, comes with many built-in functions that are readily available for use. These functions simplify coding by providing pre-defined methods for common tasks.

What are PHP Built-in Functions?

PHP built-in functions are functions that are already defined in the PHP language. This means you do not have to write the code for these functions yourself, you can simply call them in your scripts. PHP has over 1000 built-in functions that can perform a variety of tasks such as handling arrays, strings, regular expressions, dates, directories, error handling, and much more.

How to Use PHP Built-in Functions?

To use a PHP built-in function, you simply need to call the function by its name followed by parenthesis (). Inside the parenthesis, you can pass parameters if the function requires them. For example, the echo() function is used to output one or more strings. Here's how you use it:

echo("Hello, World!");

In this example, "Hello, World!" is the parameter. When you run this script, it will output: Hello, World!

Examples of PHP Built-in Functions

Let's look at some examples of commonly used PHP built-in functions.

String Functions​

  • str_replace() - This function replaces some characters with some other characters in a string.
$str = "Hello, World!";
$new_str = str_replace("World", "Dolly", $str);
echo $new_str; // Outputs: Hello, Dolly!
  • strlen() - This function returns the length of a string.
echo strlen("Hello, World!"); // Outputs: 13

Array Functions​

  • count() - This function is used to return the length (the number of elements) of an array.
$fruits = array("Apple", "Banana", "Mango");
echo count($fruits); // Outputs: 3
  • sort() - This function sorts an indexed array in ascending order.
$fruits = array("Mango", "Apple", "Banana");
sort($fruits);

// After sorting
for($x = 0; $x < count($fruits); $x++) {
    echo $fruits[$x];
    echo "<br>";
}

Mathematical Functions​

  • rand() - This function generates a random number.
echo rand(); // Outputs: Random number
  • max() - This function returns the highest value in an array, or the highest value of several specified values.
echo max(1, 3, 5, 9, 7); // Outputs: 9

Conclusion

PHP built-in functions are a powerful feature of the PHP language. They can simplify your code and make it easier to read and maintain. By mastering the use of these functions, you can become a more efficient and effective PHP programmer.