How to Fix Typeerror in PHP

Fixing TypeError in PHP

PHP 8 introduced strict type errors via TypeError exceptions when type declarations are violated. These appear frequently at runtime when data from external sources doesn't match function signatures.

Common Causes

• Passing null to non-nullable typed parameters
• String values where int or float is declared
• Return type violations in strict mode

The Fix

Enable strict types and handle null properly:

<?php
declare(strict_types=1);

class OrderService {
    public function calculateTotal(
        float $price,
        int $quantity,
        ?float $discount = null
    ): float {
        if ($price < 0 || $quantity < 0) {
            throw new InvalidArgumentException('Price and quantity must be non-negative');
        }

        $total = $price * $quantity;
        if ($discount !== null) {
            $total -= $total * ($discount / 100);
        }
        return round($total, 2);
    }
}

// Validate before calling
$price = filter_var($input['price'], FILTER_VALIDATE_FLOAT);
if ($price === false) {
    throw new TypeError('Invalid price value');
}

Use declare(strict_types=1) at the top of every file to catch type issues early rather than relying on PHP's loose type coercion.

Bugsly for PHP

Bugsly captures PHP TypeError exceptions with the function signature, actual argument types, and the call stack. This reveals exactly which external input caused the type violation.