What data types is the is_real() function applicable to? What are its use cases?

gitbox 2025-06-15

1. is_real() function's applicable data types

In PHP, the is_real() function is applicable to the following data types:

Floating-point type (float): The floating-point type refers to numbers that contain a decimal part, such as 3.14, -1.23, 0.0, etc.
Integer (int): Although the is_real() function is designed to check for floating-point types, it will return false if an integer is passed. Since integers do not have a decimal part, they cannot be considered floating-point numbers.
String (string): If the string passed can be successfully converted into a floating-point number, is_real() will return true. For example, the string "3.14" will be recognized as a floating-point number.

However, is_real() does not apply to other data types such as arrays, objects, boolean values, etc.

2. is_real() function's use cases

The is_real() function is commonly used in the following scenarios:

2.1 Data validation

When handling user input, especially when floating-point numbers are required, using is_real() can help developers validate whether the input is valid. For example:

$input = $_POST[&#039;number&#039;];
<p>if (is_real($input)) {<br>
// Handle floating-point data<br>
echo "The input is a floating-point number";<br>
} else {<br>
echo "Invalid input, please enter a floating-point number";<br>
}<br>

2.2 Type checking

Sometimes, the program may need to make different decisions based on the data type. The is_real() function can be used to check whether floating-point operations or calculations are needed. For example:

$number = 12.5;
<p>if (is_real($number)) {<br>
$result = $number * 2.5;<br>
echo "The calculation result is: " . $result;<br>
} else {<br>
echo "The input is not a floating-point type";<br>
}<br>

2.3 Data conversion

When retrieving data from a database or external system, it may be processed as a string. In some cases, the data may need to be converted from a string to a floating-point type, and is_real() can help ensure that the data is a valid floating-point number:

$data = "45.67";  // Data obtained from a database or external source
<p>if (is_real($data)) {<br>
$converted = (float)$data;<br>
echo "The converted floating-point number is: " . $converted;<br>
} else {<br>
echo "The data is not a valid floating-point type";<br>
}<br>

2.4 Mathematical operation validation

When performing mathematical calculations, it may be necessary to verify if the operands are floating-point numbers to avoid errors in calculations. For example, when performing division, it is a common requirement to check if the divisor is a floating-point type:

$a = 10;
$b = 3.14;
<p data-is-last-node="" data-is-only-node="">if (is_real($b) && $b != 0) {<br>
$result = $a / $b;<br>
echo "The division result is: " . $result;<br>
} else {<br>
echo "The divisor is not a floating-point number or is zero";<br>
}<br>

is_real