Settype for changing types in PHP - Step-by-Step Execution

Concept Flow - Settype for changing types

Start with variable

↓

Call settype(var, type)

↓

Change variable type

↓

Variable now has new type and value

↓

Use variable with new type

The flow shows how settype changes a variable's type and value, then you use the variable with its new type.

Execution Sample

PHP

<?php
$var = "123";
settype($var, "int");
echo gettype($var) . ": " . $var;
?>

This code changes a string variable to an integer and prints its type and value.

Execution Table

Step	Variable	Original Type	Action	New Type	New Value	Output
1	$var	string	Initialize with "123"	string	"123"
2	$var	string	settype($var, "int")	integer	123
3	$var	integer	echo gettype($var) . ": " . $var	integer	123	integer: 123
4	-	-	-	-	-	Execution ends

💡 After step 3, the variable is an integer with value 123, so execution ends.

Variable Tracker

Variable	Start	After settype	Final
$var	"123" (string)	123 (integer)	123 (integer)

Key Moments - 3 Insights

Why does the variable value change when we use settype?

Because settype converts the variable to the new type, PHP changes the value to match that type, as shown in step 2 of the execution_table.

Does settype return the new value or the variable itself?

settype returns a boolean true on success, but the variable itself is changed by reference, as seen in step 2 where $var changes type and value.

What happens if you settype to 'bool' with a non-empty string?

PHP converts any non-empty string to true (boolean), so the variable becomes true, similar to how it changed to integer in the example.

Visual Quiz - 3 Questions

Look at the execution_table, what is the type of $var after step 2?

A integer

B string

C boolean

D float

💡 Hint

Check the 'New Type' column in step 2 of the execution_table.

At which step does the output 'integer: 123' appear?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Output' column in the execution_table.

If we change settype($var, "int") to settype($var, "bool"), what would be the new value of $var after step 2?

A false

B true

C 0

D "bool"

💡 Hint

Recall that any non-empty string converts to true when cast to boolean in PHP.

Concept Snapshot

settype(variable, type) changes the variable's type in place.
Supported types: 'int', 'integer', 'bool', 'boolean', 'float', 'string', etc.
The variable's value changes to match the new type.
settype returns true on success.
Use gettype() to check the variable's type after conversion.

Full Transcript

This example shows how PHP's settype function changes a variable's type and value. Initially, $var is a string with value "123". After calling settype($var, "int"), $var becomes an integer with value 123. When we print the type and value, it outputs 'integer: 123'. The variable changes by reference, and settype returns true. This helps convert variables to needed types easily.