PHP Variables

Think of a variable as a labelled box. You put a value inside the box and give the box a name. Later you use the name to get the value back.

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<?php
$city = "Jaipur";
$population = 3000000;

echo $city;
echo "\n";
echo $population;

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Jaipur
3000000

How to create a variable

A PHP variable has three parts:

1. The dollar sign $ at the start.
2. A name, such as city.
3. A value, given with the = sign.

There is no keyword like let or var. You create a variable simply by giving it a value for the first time.

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<?php
$price = 250;

PHP works out the type for you

You do not declare that $price is a number. PHP looks at the value and decides. That is called dynamic typing.

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<?php
$value = 10;       // a number
$value = "ten";    // now a string
echo $value;

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ten

This is flexible, but it can also hide bugs. Later in the course you will learn type declarations that make your code safer.

Using variables in text

Put a variable inside double quotes and PHP replaces it with its value.

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<?php
$name = "Neha";
echo "Hello, $name!";

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Hello, Neha!

Why we use variables

Without variables you would repeat the same value in many places. With a variable, you write it once and change it in one spot.

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<?php
$siteName = "Code Corner";

echo "Welcome to $siteName\n";
echo "Thanks for visiting $siteName";

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Welcome to Code Corner
Thanks for visiting Code Corner

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<?php
$name = "Asha";
$age = 24;
$city = "Kochi";

echo "$name is $age and lives in $city.";

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Asha is 24 and lives in Kochi.