PHP Type Casting

Type casting changes a value from one type to another on purpose. A cast is written as a type name in parentheses just before the value.

A float cast to int

<?php
var_dump((int) 12.9);

Numeric text cast to int

<?php
var_dump((int) "12.9");

Text cast to float

<?php
var_dump((float) "2.5");

A number cast to string

<?php
var_dump((string) 42);

Example

<?php
$priceA = "10";
$priceB = "2.5";
$total = (int) $priceA + (float) $priceB;
echo $total, "\n";

Key points

A cast produces a value of the chosen type from the value given.
The (int) cast cuts a fraction away instead of rounding it.
Text that holds a number casts to that number.
The (float) cast turns a whole value or numeric text into a float.
The (string) cast turns a number into text.
var_dump shows the type a cast produced, so the change is easy to check.

In this example, the two prices arrive as text, the way a form sends values. The casts change "10" to the integer 10 and "2.5" to the float 2.5. The sum is 12.5, and echo prints it.

Note

Casting makes a new value, and the value cast from keeps its old type.

Try it Yourself

Edit the code, then press Run.

Running is simulated

<?php
$priceA = "10";
$priceB = "2.5";
$total = (int) $priceA + (float) $priceB;
echo $total, "\n";

Exercise

What does var_dump((int) 7.8); print?

int(7) int(8) float(7.8) int(7.8)