If-else Block

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Programming is all about choices. Everything you do in code boils down to answering a question: What should happen if X condition is true? That is where PHP’s if-else block steps in. if-else helps you control the flow of your program.

In this tutorial, you will understand how the if-else block works with examples.

What Exactly Is an If-Else Block?

The else block is the final part of an if statement, executed when none of the other conditions are true.

Block of else in if statement

Think of the if-else block as the decision-making engine of your PHP code. It allows you to define, "If this condition is met, take this action; otherwise, handle it differently."

Here is the basic structure:

if (condition) {
    
} else {
    // Code to run if the condition is false
}

So, the if part checks a condition. If it is false, the else runs a code in else {} block.

Let's say you are creating a website that greets visitors based on their login status. Here is how you would do it:

$isLoggedIn = true;

if ($isLoggedIn) {
    echo "Welcome back!";
} else {
    echo "Please log in to continue.";
}
  • If $isLoggedIn is true, your user gets a warm "Welcome back!" message.
  • Otherwise, they will need to log in.

Let's move on to the following section to see more examples.

Examples of PHP if else Block

Else with No Curly Braces

Using this syntax, you are limited to a single statement—trying to include multiple statements without curly braces will not work.

$is_logged = false;
if ( $is_logged ) 
  echo "Welcome to flatcoding.com";
else 
  echo "Invalid Username or Password";

You can also use it with other languages like JavaScript, HTML, and more. Let's see how you can do that in the below section.

PHP IF Else with Embedded Syntax

Here, you can mix PHP code with HTML markup or other content. If the condition does not pass, it outputs something different. Take a look at this example:

<!DOCTYPE html>
<html>
  <head>
    <title>The PHP IF ELSE</title>
    <?php if ( false ): ?>
    <?php else: ?>
       <script type="javascript">alert("Hello World");</script>
    <?php endif;?>
  </head>
  <body>
     <h1>Welcome to Home Page !</h1>
  </body>
</html>

In this example, the JavaScript code runs when the main if statement does not meet the condition.

Let's summarize it

Wrapping Up

The if-else statement is used to execute PHP statements when the if condition fails to evaluate to the true boolean value.

Here is a quick example:

if ( false ) {
  
} else {
  // This block executes once the if condition fails to execute.
}

Additionally, the if-else statement can be written with curly braces, without braces, or with embedded syntax, and here you can use it with any other language as well.

Thank you for reading. Happy Coding!

Frequently Asked Questions (FAQs)

  • What is an if-else block in PHP?

    An if-else block in PHP is a structure that allows you to execute specific code when a condition is true and alternative code when it is false.

  • What is the purpose of the else block in PHP?

    The else block is executed when the condition in the if statement evaluates to false. It provides an alternative set of instructions. What is the basic syntax of an if-else block? 
    if (condition) {  
    // Code to run if the condition is true  
} else {  
    // Code to run if the condition is false  
}

  • Can you provide an example of using if-else in PHP?

    Here is an example of using if-else to greet a user based on login status: 
    $isLoggedIn = true;  
if ($isLoggedIn) {  
    echo "Welcome back!";  
} else {  
    echo "Please log in to continue.";  
}

  • How does the if-else block work without curly braces?

    If curly braces are omitted, only one statement can be executed for each condition. For example: 
    $is_logged = false;  
if ($is_logged)  
    echo "Welcome to flatcoding.com";  
else  
    echo "Invalid Username or Password";

  • Can PHP's if-else block be used with embedded syntax?

    Yes, you can embed PHP code within HTML markup.

  • When does the JavaScript code run in the embedded syntax example?

    The JavaScript code runs when the condition in the main if statement is false.

  • What is the key takeaway about the else block?

    The else block provides an alternative set of instructions when the condition in the if statement is not met. For example: 
    else {  
    echo "Block of code to be executed";  
}
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