Cast

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This package contains a strong typed utility class for safely testing and casting mixed values to bool, float, int, or string values.

Rationale

What is the purpose of this package and why is it necessary? PHP is a great language, however is has some quirks. One of them is that PHP will convert any string to an integer even when strict type is set.

The following code will not cause any error or warning (tested with PHP 7.2.12):

<?php
declare(strict_types=1);

ini_set('display_errors', '1');
error_reporting(E_ALL);

echo '1: ', (int)'3.14', PHP_EOL;
echo '2: ', (int)'123abc', PHP_EOL;
echo '3: ', (int)"Ceci n'est pas une pipe.", PHP_EOL;
echo '4: ', (int)'', PHP_EOL;
echo '5: ', (int)null, PHP_EOL;

but gives the following output:

1: 3
2: 123
3: 0
4: 0
5: 0

This package provides a strong typed utility class for safely testing and casting mixed typed values to Boolean, float, integer, or string values.

Manual

The class SetBased\Helper\Cast has the following methods for testing mixed values against primitive data types:

Method	Null Value	Return Type
isManBool	returns false	bool
isManFloat	returns false	bool
isManFiniteFloat	returns false	bool
isManInt	returns false	bool
isManString	returns false	bool
isOptBool	returns true	bool
isOptFloat	returns true	bool
isOptFiniteFloat	returns true	bool
isOptInt	returns true	bool
isOptString	returns true	bool

The class SetBased\Abc\Helper\Cast has the methods shown in the table below for casting mixed values to a primitive data type. When a value can not cast an exception will be thrown.

Method	Null Value	Return Type
toManBool	throws an exception	bool
toManFloat	throws an exception	float
toManFloatInclusive	throws an exception	float
toManInt	throws an exception	int
toManString	throws an exception	string
toOptBool	returns null	bool|null
toOptFloat	returns null	float|null
toOptFloatInclusive	returns null	float|null
toOptInt	returns null	int|null
toOptString	returns null	string|null

Remarks:

• 'opt' is short for optional: null values are valid. Testing and casting against null yields true and null, respectively.
• 'man' is short for mandatory: null values are not allowed. Testing against null yields false and casting null will throw an exception.

Sample

Code:

<?php
declare(strict_types=1);

use SetBased\Helper\Cast;

$value = "Ceci n'est pas une pipe.";
if (Cast::isManInt($value))
{
  echo 'This is not an integer', PHP_EOL;
}
else
{
  echo Cast::toManInt($value), PHP_EOL;
}

echo Cast::toManFloat($value), PHP_EOL;

Output:

This is not an integer

Exception

Finite Floats

A float can be finite (e.g. 3.14), infinite (i.e. INF or -INF), or not a number (i.e. NAN). The [is|to][Man|Opt]FiniteFloat methods will assist in establishing a value is a real floating point number.

Booleans

Only and only the following values are valid representations of boolean values:

• false
  • int(0)
  • string(1) "0"
  • bool(false)
• true
  • int(1)
  • string(1) "1"
  • bool(true)

Hence, only these values can be cast safely to booleans and vice versa.

Installing

composer require setbased/helper-cast

References

• PHP RFC: Safe Casting Functions
• A functional and closer to the original RFC implementation theodorejb/PolyCast .

License

This project is licensed under the MIT license.