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PHP Is Conditional Functions

? PHP Is Conditional Functions

? Quick Overview

In PHP, is conditional functions are used to check whether a variable is of a certain type or has a specific property. They help ensure data correctness before processing.

? Key Concepts

  • is_array() — Checks if a variable is an array
  • is_bool() — Checks if a variable is boolean
  • is_float() — Checks if a variable is float
  • is_int() — Checks if a variable is integer
  • is_null() — Checks if a variable is NULL
  • is_numeric() — Checks numeric values or numeric strings
  • is_object() — Checks if a variable is an object
  • is_string() — Checks if a variable is string

? Syntax / Theory

Each is function returns true or false. They are commonly used inside conditional statements to validate data types before performing operations.

? Code Example

? View Code Example
// Checking different variable types using PHP is_* functions
";
}

if (is_string($var2)) {
echo "$var2 is a string.
";
}

if (is_float($var3)) {
echo "$var3 is a float.
";
}

if (is_bool($var4)) {
echo "$var4 is a boolean.
";
}

if (is_null($var5)) {
echo "var5 is NULL.
";
}
?>

? Live Output / Explanation

The script evaluates each variable using appropriate is functions and prints messages only when conditions return true.

? Interactive Diagram

Variable is_* Check True / False

? Use Cases

  • Validating user input before calculations
  • Ensuring correct data types in APIs
  • Preventing runtime errors
  • Handling dynamic data sources safely

✅ Tips & Best Practices

  • Use is_numeric() for numeric user inputs
  • Combine multiple checks with logical operators
  • Validate variables before using them in logic

? Try It Yourself

  • Add an array and test it using is_array()
  • Check numeric strings with is_numeric()
  • Create a class and validate it using is_object()