Current Location: Home> Latest Articles> How to Use is_double and is_int Together to Efficiently Distinguish Between Floats and Integers

How to Use is_double and is_int Together to Efficiently Distinguish Between Floats and Integers

M66 2025-07-10

How to Use is_double and is_int Together to Efficiently Distinguish Between Floats and Integers

In PHP, is_int and is_double are two commonly used type-checking functions. is_int is used to determine whether a value is an integer, while is_double checks if a value is a float. Although the purpose of these functions is straightforward, when we want to more efficiently determine whether a variable is a float or an integer, simply calling is_int and is_double separately may raise some performance concerns, especially in performance-sensitive applications.

Type Checking in PHP

In PHP, is_int() and is_double() are built-in functions used for checking variable types. is_int() checks whether a variable is an integer, returning true if it is, and false otherwise. is_double() (also usable as is_float()) checks whether a variable is a float, returning true if it is a float, and false otherwise.

These functions are typically used to determine a single type. However, they can also be used together to distinguish between integers and floats. The challenge is that PHP automatically converts values between types in many scenarios, especially with numeric strings and other non-primitive types, which requires more precise differentiation.

Issues with Using is_int and is_double Separately

When we use is_int() or is_double() independently to check variable types, we might encounter the following issues:

  1. Type Conversion: PHP supports automatic type conversion, which means some values that appear to be integers—like 1.0—might be misidentified as integers.

  2. Performance Overhead: Each call to is_int() or is_double() performs a type check. In complex logic, this can introduce minor performance overhead.

  3. Inaccuracy: For types like numeric strings or booleans, is_int() and is_double() might not produce accurate results.

Optimizing the Use of is_int and is_double Together

To more efficiently distinguish between floats and integers, we can combine PHP’s type-checking functions with additional logic to make our checks more accurate.

1. Checking if a Variable is an Integer

First, use is_int() to check if a variable is an integer. If it returns true, there's no need for further checks.

$value = 5;
if (is_int($value)) {
    echo "This is an integer.";
}

2. Checking if a Variable is a Float

When checking for floats, use is_double() along with a check to ensure is_int() does not return true. This prevents misidentifying values like 1.0 as integers.

$value = 5.5;
if (is_double($value) && !is_int($value)) {
    echo "This is a float.";
}

3. Using is_numeric for Numeric Strings

If you're working with numeric strings, use is_numeric() to first determine if the string can be interpreted as a number. Then apply is_int() and is_double() to identify the exact type.

$value = "10.5";  // Numeric string
if (is_numeric($value)) {
    if (strpos($value, '.') !== false) {
        echo "This is a float.";
    } else {
        echo "This is an integer.";
    }
}

4. Summary and Optimization

By combining is_int(), is_double(), and is_numeric(), we can accurately and efficiently identify variable types, avoiding potential pitfalls in performance or type misidentification. For more complex scenarios, it’s recommended to use is_numeric() as an initial filter, and then refine your logic as needed.

This optimized approach helps us distinguish between floats and integers more accurately, while also improving code readability and execution efficiency.

Related