PHP Variables

In PHP, a variable is a container for storing values such as numbers, strings, arrays, and objects. Variables in PHP are dynamically typed, meaning you don’t need to declare a data type for a variable when you create it.

Here are some examples of how to declare and use variables in PHP:

<?php
// Declare a variable and assign a value
$name = "John Doe";
// Output the value of the variable
echo $name; // Output: John Doe
// Update the value of the variable
$name = "Jane Doe";
// Output the new value of the variable
echo $name; // Output: Jane Doe
?>

In the example above, we declare a variable called $name and assign the value “John Doe” to it. We then output the value of the variable using the echo statement. We then update the value of the variable to “Jane Doe” and output the new value using echo.

Variables can also be used in mathematical operations:

<?php
// Declare two variables and assign values
$num1 = 10;
$num2 = 5;
// Perform mathematical operations using the variables
$sum = $num1 + $num2;
$difference = $num1 - $num2;
$product = $num1 * $num2;
$quotient = $num1 / $num2;
// Output the results
echo "Sum: " . $sum . "<br>"; // Output: Sum: 15
echo "Difference: " . $difference . "<br>"; // Output: Difference: 5
echo "Product: " . $product . "<br>"; // Output: Product: 50
echo "Quotient: " . $quotient . "<br>"; // Output: Quotient: 2
?>

In this example, we declare two variables called $num1 and $num2 and assign the values 10 and 5 respectively. We then perform mathematical operations using these variables and store the results in new variables $sum, $difference, $product, and $quotient. We then output the results using echo.

Variables can also be used with strings:

<?php
// Declare a variable and assign a string value
$name = "John Doe";
// Output a string that includes the variable
echo "Hello, " . $name . "!"; // Output: Hello, John Doe!
?>

In this example, we declare a variable called $name and assign the value “John Doe” to it. We then output a string that includes the variable using the echo statement.

Finally, variables can also be used with arrays:

<?php
// Declare an array variable
$fruits = array("Apple", "Banana", "Orange");
// Output the value of an element in the array using its index
echo $fruits[1]; // Output: Banana
// Update the value of an element in the array
$fruits[1] = "Mango";
// Output the new value of the element
echo $fruits[1]; // Output: Mango
?>

In this example, we declare an array variable called $fruits and assign the values “Apple”, “Banana”, and “Orange” to it. We then output the value of an element in the array using its index. We then update the value of an element in the array and output the new value.