| Introduction to Web Development |
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| Basic PHP Syntax |
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| PHP Basics |
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| Variables and Data Types |
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| Functions in PHP |
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| User-defined Functions |
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| Built-in Functions |
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| Variable Scope |
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| Include and Require |
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| Working with Forms |
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| Forms in HTML |
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| Form Handling in PHP |
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| Working with Files |
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| File Handling |
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| File System Functions |
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| Working with Databases |
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| Introduction to Databases |
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| Advanced PHP Techniques |
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| Object-Oriented Programming (OOP) |
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| Error and Exception Handling |
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Conditional statements in PHP are used to perform different actions based on different conditions. These statements help control the flow of the program, allowing certain code blocks to execute only if specified conditions are met. Here’s an in-depth look at the different types of conditional statements in PHP:
1. if Statement
The if statement is the most basic conditional statement, which executes a block of code if a specified condition is true.
Syntax:
if (condition) {
// Code to be executed if condition is true
}
Example:
$age = 20;
if ($age >= 18) {
echo "You are an adult.";
}
2. 'else' Statement
The ‘else‘ statement is used together with ‘if‘. It executes a block of code if the condition in the ‘if‘ statement is false.
Syntax:
if (condition) {
// Code to be executed if condition is true
} else {
// Code to be executed if condition is false
}
Example:
$age = 16;
if ($age >= 18) {
echo "You are an adult.";
} else {
echo "You are a minor.";
}
3. 'elseif' Statement
The ‘elseif‘ statement is used to specify a new condition if the first condition is false. You can use multiple ‘elseif‘ statements to check multiple conditions.
Syntax:
if (condition1) {
// Code to be executed if condition1 is true
} elseif (condition2) {
// Code to be executed if condition1 is false and condition2 is true
} else {
// Code to be executed if condition1 and condition2 are both false
}
Example:
$score = 75;
if ($score >= 90) {
echo "A";
} elseif ($score >= 80) {
echo "B";
} elseif ($score >= 70) {
echo "C";
} else {
echo "F";
}
4. switch Statement
The switch statement is used to perform different actions based on different conditions. It’s an alternative to using multiple ‘elseif‘ statements and can make the code more readable.
Syntax:
switch (n) {
case value1:
// Code to be executed if n=value1
break;
case value2:
// Code to be executed if n=value2
break;
// You can have any number of case statements
default:
// Code to be executed if n doesn't match any case
}
Example:
$day = "Wednesday";
switch ($day) {
case "Monday":
echo "Today is Monday.";
break;
case "Tuesday":
echo "Today is Tuesday.";
break;
case "Wednesday":
echo "Today is Wednesday.";
break;
default:
echo "Today is not Monday, Tuesday, or Wednesday.";
}
Detailed Example with Nested Conditions
Sometimes, you may need to nest conditions within each other to perform more complex checks.
Example:
$day = "Wednesday";
switch ($day) {
case "Monday":
echo "Today is Monday.";
break;
case "Tuesday":
echo "Today is Tuesday.";
break;
case "Wednesday":
echo "Today is Wednesday.";
break;
default:
echo "Today is not Monday, Tuesday, or Wednesday.";
}
n this example, the outer ‘if‘ statement checks if the age is 18 or above, and the nested ‘if‘ statements check the gender.
Key Points
- Condition: Can be any expression that returns a boolean value (
trueorfalse). - Break Statement: Used inside
switchto terminate the current case and prevent fall-through to the next case. - Default Case: Optional; executed if none of the cases match.
These conditional statements are essential for controlling the flow of a PHP program, making decisions, and executing specific blocks of code based on those decisions.
