Verifying Integer Data Types in PHP

When dealing with numeric data in PHP, determining whether a variable represents an integer can be crucial. To address this, the is_int() function is commonly employed. However, its behavior can sometimes be unexpected, leading to confusion.

To rectify this, we introduce alternative methods for validating integer data types:

FILTER_VALIDATE_INT

Using this method, you can efficiently assess whether a variable represents an integer:

if (filter_var($variable, FILTER_VALIDATE_INT) === false) {
  // Variable is not an integer
}

This approach accurately handles integers, floating-point numbers, and even strings.

CASTING COMPARISON

By converting the variable to an integer and comparing it to its original form as a string, you can determine its integer nature:

if (strval($variable) !== strval(intval($variable))) {
  // Variable is not an integer
}

This method ensures that only true integers are considered integers.

CTYPE_DIGIT

To limit your validation to non-negative integers (0 or greater), you can utilize the ctype_digit() function:

if (!ctype_digit(strval($variable))) {
  // Variable is not an integer
}

This approach focuses on positive integers and zero, providing a more specific validation.

REGULAR EXPRESSION

Employing regular expressions offers another option for validating integers:

if (!preg_match('/^-?\d $/', $variable)) {
  // Variable is not an integer
}

This method validates integers, whether positive or negative, and excludes floating-point numbers or strings.