if Statements in PHP

By: Andi, Stig and Derick Emailed: 1643 times Printed: 2113 times    

Latest comments
By: rohit kumar - how this program is work
By: Kirti - Hi..thx for the hadoop in
By: Spijker - I have altered the code a
By: ali mohammed - why we use the java in ne
By: ali mohammed - why we use the java in ne
By: mizhelle - when I exported the data
By: raul - no output as well, i'm ge
By: Rajesh - thanx very much...
By: Suindu De - Suppose we are executing

if statements are the most common conditional constructs, and they exist in most programming languages. The expression in the if statement is referred to as the truth expression. If the truth expression evaluates to true, the statement or statement list following it are executed; otherwise, they’re not.

You can add an else branch to an if statement to execute code only if all the truth expressions in the if statement evaluated to false:

if ($var >= 50) {

print '$var is in range';

} else {

print '$var is invalid';


Notice the braces that delimit the statements following if and else, which make these statements a statement block. In this particular case, you can omit the braces because both blocks contain only one statement in them. It is good practice to write these braces even if they’re not syntactically required. Doing so improves readability, and it’s easier to add more statements to the if block later (for example, during debugging).

The elseif construct can be used to conduct a series of conditional checks and only execute the code following the first condition that is met.

For example:

if ($num < 0) {

print '$num is negative';

} elseif ($num == 0) {

print '$num is zero';

} elseif ($num > 0) {

print '$num is positive';


Statement Statement List

if (expr)


elseif (expr)


elseif (expr)





if (expr):

statement list

elseif (expr):

statement list

elseif (expr):

statement list



statement list



The last elseif could be substituted with an else because, if $num is not negative and not zero, it must be positive.

Note: It’s common practice by PHP developers to use C-style else if notation instead of elseif.

Both styles of the if construct behave in the same way. While the statement style is probably more readable and convenient for use inside PHP code blocks, the statement list style extends readability when used to conditionally display HTML blocks. Here’s an alternative way to implement the previous example using HTML blocks instead of print:

<?php if ($num < 0): ?>

<h1>$num is negative</h1>

<?php elseif($num == 0): ?>

<h1>$num is zero</h1>

<?php elseif($num > 0): ?>

<h1>$num is positive</h1>

<?php endif; ?>

As you can see, HTML blocks can be used just like any other statement. Here, only one of the HTML blocks are displayed, depending on the value of $num.

Note: No variable substitution is performed in the HTML blocks. They are always printed as is.


PHP Home | All PHP Tutorials | Latest PHP Tutorials

Sponsored Links

If this tutorial doesn't answer your question, or you have a specific question, just ask an expert here. Post your question to get a direct answer.

Bookmark and Share


1. View Comment

i9s this such a hard ?

my head was drilling over here!

View Tutorial          By: shadow_5566 at 2009-05-14 01:32:01

Your name (required):

Your email(required, will not be shown to the public):

Your sites URL (optional):

Your comments:

More Tutorials by Andi, Stig and Derick
Execution Lifetime of a PHP script
preg_split() and explode() in PHP
preg_replace() and preg_replace_callback() in PHP
preg_match(), function preg_match_all(), preg_grep() in PHP
tmpfile() in PHP
Renaming and Removing Files in PHP
Locking files in PHP
File Handling in PHP
Handling BLOB in PHP and MySQL
Using Sessions in PHP
Using Cookies in PHP
Using PEAR::Crypt_HMAC in PHP
Using HMAC Verification in PHP
Input Validation in PHP
__autoload() METHOD in PHP

More Tutorials in PHP
PHP code to import from CSV file to MySQL
PHP code to write to a CSV file from MySQL query
PHP code to write to a CSV file for Microsoft Applications
Convert XML to CSV in PHP
Password must include both numeric and alphabetic characters - Magento
PHP file upload (Large Files)
PHP file upload prompts authentication for anonymous users
PHP file upload with IIS on windows XP/2000 etc
Error: Length parameter must be greater than 0
Multiple File Upload in PHP using IFRAME
Resume or Pause File Uploads in PHP
Exception in module wampmanager.exe at 000F15A0 in Windows 8
Handling file locks in PHP
HTML table output using Nested for loops in PHP
Count occurrences of a character in a String in PHP

More Latest News
Most Viewed Articles (in PHP )
Handling BLOB in PHP and MySQL
Execution Lifetime of a PHP script
A Basic Example using PHP in AWS (Amazon Web Services)
isset() function in PHP
Traversing Arrays Using list() and each() in PHP
Constants in PHP
if Statements in PHP
public, protected, and private Properties in PHP
public, protected, and private Methods in PHP
Static Methods in PHP
Extract files from a .zip file using PHP
Reading Cookie Values in PHP
Generate random timestamp between two dates
Installing PHP with nginx-server under windows
Convert a hex string into a 32-bit IEEE 754 float number in PHP
Most Emailed Articles (in PHP)
File Handling in PHP
GDBM, NDBM, DB2, DB3, DBM, and CDB Databases in PHP
Perl's Encoding::FixLatin equivalent in PHP
Function within another function in PHP
func_get_arg() and func_get_args() functions in PHP
extract() in PHP
call_user_func() or call_user_func_array() functions in PHP
use() in PHP
break out of an if() block in PHP
PHP code to write to a CSV file from MySQL query
isset() function in PHP
Binary Operators in PHP
Comparison operators in PHP
do...while Loops in PHP
Destructors in PHP