PHP 5 if..else..elseif Statements

Conditional statements are used to perform different actions based on different conditions.

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PHP Conditional Statements

Very often when you write code, you want to perform different actions for different decisions. You can use conditional statements in your code to do this.
In PHP we have the following conditional statements:

• if statement - executes some code only if a specified condition is true
• if...else statement - executes some code if a condition is true and another code if the condition is false
• if...elseif....else statement - selects one of several blocks of code to be executed
• switch statement - selects one of many blocks of code to be executed

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PHP - The if Statement

The if statement is used to execute some code only if a specified condition is true.

Syntax

if (condition) {
  code to be executed if condition is true;
}

The example below will output "Have a good day!" if the current time (HOUR) is less than 20:

Example

<?php
$t=date("H");

if ($t<"20") {
  echo "Have a good day!";
}
?>

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PHP - The if...else Statement

Use the if....else statement to execute some code if a condition is true and another code if the condition is false.

Syntax

if (condition) {
  code to be executed if condition is true;
} else {
  code to be executed if condition is false;
}

The example below will output "Have a good day!" if the current time is less than 20, and "Have a good night!" otherwise:

Example

<?php
$t=date("H");

if ($t<"20") {
  echo "Have a good day!";
} else {
  echo "Have a good night!";
}
?>

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PHP - The if...elseif....else Statement

Use the if....elseif...else statement to select one of several blocks of code to be executed.

Syntax

if (condition) {
  code to be executed if condition is true;
} elseif (condition) {
  code to be executed if condition is true;
} else {
  code to be executed if condition is false;
}

The example below will output "Have a good morning!" if the current time is less than 10, and "Have a good day!" if the current time is less than 20. Otherwise it will output "Have a good night!":

Example

<?php
$t=date("H");

if ($t<"10") {
  echo "Have a good morning!";
} elseif ($t<"20") {
  echo "Have a good day!";
} else {
  echo "Have a good night!";
}
?>