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PHP Functions

In PHP a function is a predefined set of commands that are carried out when the function is called. In addition to being able to write your own functions, PHP has a number of predefine functions for you to use. Below are many functions we discuss in our various tutorials, with simple definitions and examples to follow.

Eval () PHP Function
How to evaluate the inputed text string as PHP using the eval function

IF - Using IF in PHP
IF - We use if in PHP to make a decision

Atan2 () PHP Function
How to calculate the arc tangent of two coordinates in radians using PHP

GoTo
How tutorial of how to use GoTo in PHP to skip over code.

<Script> Tags
How to use PHP in a file that supports mixed scripting languages using the <script> tags

Abs () PHP Function
How to use the ABS () function in PHP to return the absolute value of a number

Acos () PHP Function
How to use the acos function to return the arccosine of a number using PHP.

Addslashes () PHP Function
Addslashes adds back slashes into your form data

Array () PHP Function
Array () PHP Function

Asin () PHP Function
How to find the arcsine (asin) of a number using PHP.

Atan () PHP Function
This PHP function allows you to find the arctangent of a value in radians.

Base_convert () PHP Function
Converting one number base to another using PHP

Bindec () PHP Function
The bindec function is used to convert a binary string to a decimal in PHP.

Cal_days_in_month () PHP Function
This PHP function tells you how many days are in a given month in a given year.

Ceil () PHP Function
Always rounding a number up to the nearest whole number

Cos () PHP Function
How to calculate the cosine of a number, in radians, using PHP.

Cosh () PHP Function
How to use the Cosh function in PHP to find the hyperbolic cosine

Crypt () PHP Function
The crypt () function encrypts data in PHP

Date () PHP Function
Use date to format the time () function's output.

Decbin () PHP Function
The Decbin PHP Function is used to convert a decimal into a binary number.

Dechex () PHP Function
The dechex function is used to convert a decimal number into a hexadecimal number.

Decoct () PHP Function
The Decoct PHP Function is used to convert a decimal into an octal number

Easter_date () PHP Function
PHP function that calculates what day Easter Sunday falls on in any given year.

Echo () PHP Function
Echo () PHP Function

Else () PHP Function
Else () is used to give an alternate set of code to execute when the if () part of a statement is false.

Elseif () PHP Function
Elseif () is used in conditional statements to make choices.

Eval () PHP Function
Eval () is used to evaluate its input string as PHP code

Exp () PHP Function
The Exp () PHP Function is used to calculate e raised to the power of x.

Feof () PHP Function
The FEOF PHP function is used to test for the end of the file.

Fgets () PHP Function
Fgets is a PHP function that gets data from an external file line by line.

File () PHP Function
File () pulls data from an outside file and puts it into an array .

File_Get_Contents () PHP Function
File_get_contents reads the data from a file and returns it to the PHP file as a string

Floor () PHP Function
Always rounding a number down to the nearest whole number

Fopen () PHP Function
Use fopen() to open a file from php

For () PHP Function
For () is a form of loop in PHP

Foreach () PHP Function
Foreach () is a form of loop in PHP

Fread () PHP Function
Fread is a php function used to read the contents of a file and report the data back to the php file.

Fwrite () PHP Function
fwrite is a binary safe file write used to write to a file in PHP

Getenv () PHP Function
Free tutorial about how to use the getenv() command in PHP to get such things as the document root, or the user's IP address.

Get_magic_quotes_gpc () PHP Function
Checks if Magic Quotes is turned on or off in your php configuration

Hexdec () PHP Function
The Hexdec () PHP Function is used to convert a hexadecimal into a decimal number

Htmlspecialchars () PHP Function
Htmlspecialchars is used to convert special characters to HTML entities

Hypot () PHP Function
How to calculate the Hypotenuse of a right triangle using PHP and the hypot function

If () PHP Function
If () is used as a conditional statement in PHP

ImageColorAllocate () PHP Function
The ImageColorAllocate () function is used in PHP to set the color for an image you are creating.

Imagecreate () PHP Function
The imagecreate () function is used in PHP to create a new palette based image

Imagecreatetruecolor () PHP Function
The imagecreatetruecolor () function is used in PHP to create a new true color image

Imageellipse () PHP Function
Used to draw an ellipse in PHP using the GD Library

Imagefilledarc () PHP Function
Used to draw arcs or pie graphs in PHP using the GD Library

ImageLine () PHP Function
Used to draw a line in PHP using the GD Library

Imagepolygon () PHP Function
How to draw a polygon in PHP using the imagepolygon function and assigning the coordinates of each corner

Imagerotate () PHP Function
How to rotate an image using PHP with the GD Library

Imagestring () PHP Function
Image String is used to add a string (text) to an image

Include () PHP Function
Include external files within a PHP file

Is_Binary () PHP Function
This Is_Binary function in PHP is used to check if the input is a binary number.

Is_Numeric () PHP Function
The PHP function is_numeric is used to check if a variable is a number.

Is_string () PHP Function
The is_string php function is used to check if the value is a string. It will return true or false.

Mail () PHP Function
Sending email from PHP with mail ()

Max () PHP Function
The Max () php function returns the largest number in an array or group of numbers

Min () PHP Function
The Min () php function returns the lowest number in an array or group of numbers

Mktime () PHP Function
Mktime is used to get the timestamp for a specific date

Mysql_close () PHP Function
How to close a MySQL Connection from a PHP file

Mysql_connect() PHP Function
How to connect to your MySQL database from a PHP document

Mysql_error () PHP Function
Report an error into PHP from MySQL when your SQL code encounters problems

Number_format () PHP Function
Format the decimal and 1000 separators, as well as the number of decimals places in a number

Octdec () PHP Function
The Octdec PHP Function is used to convert from an octal number to a decimal

PHP Log () Function
How to use the PHP Log function to find the natural logarithm.

PHPinfo () PHP Function
Learn more about the version of PHP your server is running using the php info command to see your version, path, and specific settings.

Pi () PHP Function
How to use the PI () PHP function as well as M_PI, M_PI_2, M_PI_4, M_1_PI, M_2_PI, M_SQRTPI, M_2_SQRTPI in your PHP code

Pow () PHP Function
How to use exponents in PHP to raise a number to the power of another number.

Preg_grep () PHP Function
Using Preg_grep to search an array and return an array

Preg_match () PHP Function
Searching a string and returning a true or false with preg_match

Preg_match_all () PHP Function
Searching an entire string for specified terms, and outputting to an array

Preg_replace () PHP Function
Performing a find and replace on a string or an array.

Preg_split () PHP Function
Splitting a string into an array based on your specifications

Print () PHP Function
Print () PHP Function

Print_r () PHP Function
Print_R is used to return an array in a human readable form in PHP

Rad2Deg () PHP Function
The Rad2Deg PHP Function is used to convert an angle measured in radians to one measured in degrees.

Rand () PHP Function
Generating a random number in PHP with the rand () function

Require () PHP Function
Include external files within a PHP file

Round () PHP Function
Rounding a number to a specified amount of decimals

Session_destroy () PHP Function
Session_destroy () is used to destroy all the data in a current session

Session_set_cookie_params () PHP Function
Session_set_cookie_params () is used to set the duration of a session cookie, as well as other optional cookie information

Session_start() PHP Function
The session_start() function is used at the beginning of all PHP pages utilizing sessions.

Session_unset () PHP Function
Session_unset() is used to clear all the variables in a session

Setcookie () PHP Function
A cookie is used to store information about a user on their computer

Sin () PHP Function
How to use the sine (sin) function to do mathematics in PHP

Sinh () PHP Function
How to use the Sinh PHP Function to determine the hyperbolic sine in PHP

Sqrt () PHP Function
Sqrt () PHP Function

Stripslashes () PHP Function
Stripslashes is used to remove blackslashes from data in php

Str_replace () PHP Function
Str_replace is used to find and replace parts of a string in PHP

Substr () PHP Function
How to use the Stbstr PHP Function to return part of a string in PHP

Switch () PHP Function
The PHP switch () function is used in replace of multiple if or elseif statements.

Tan () PHP Function
How to use the tangent (tan) function to do mathematics in PHP

Tanh () PHP Function
The Tanh PHP Function is used to find the hyperbolic tangent of the imputed number.

Time () PHP Function
Accessing the server time and formatting it

Uniqid () PHP Function
PHP code to generate a random unique user ID

Unset () PHP Function
Unset is used to destroy specified variables in PHP

While () PHP Function
While () is a form of loop in PHP

All PHP Functions
Learn all available PHP functions and what use each of them does in PHP.

Variations of Pi
The different mathematical variations of PI built into PHP.

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