PHP Variables
A variable is a named box that holds a value. The value in the box can change while the program runs.
Make a variable and print it
The first line stores text in $name. The second line prints the stored value.
<?php
$name = "Hana";
echo $name, "\n";Change the value
The name stays the same here. A new value replaces the old one, and the second print shows it.
<?php
$name = "Hana";
echo $name, "\n";
$name = "Mina";
echo $name, "\n";Add two variables
Two variables hold numbers here. A third variable holds their sum.
<?php
$apples = 4;
$pears = 3;
$total = $apples + $pears;
echo $total, "\n";Case makes two names
The names $name and $Name differ only in case. PHP treats them as two different variables.
<?php
$name = "Hana";
$Name = "Mina";
echo $name, "\n";
echo $Name, "\n";Example
<?php
$name = "Hana";
$age = 30;
echo "Name: ";
echo $name, "\n";
echo "Age: ";
echo $age, "\n";Key points
- Every variable name starts with a $ sign.
- A name starts with a letter or an underscore after the $ sign.
- Letters, numbers and underscores can follow the first character of a name.
- No type is declared for a variable.
- PHP works out the type of a variable from its value.
- Variable names are case sensitive, and keywords are not.
- A variable holds a value under a name, so the program can use that value by its name.
In this example, $name holds the text Hana. $age holds the number 30. A label prints before each value, so the name and the age sit on labelled lines.
Try it Yourself
Edit the code, then press Run.
Running is simulated · Programiz PHP Compiler
Exercise
Which line stores the number 5 in a variable named count?