Why is declare(strict_types=1); important -- test with spurious (extra) arguments passed to methods

test-spurious-arguments.php

<?php
declare(strict_types=1);

//see results:
//using declare(strict_types=1): https://3v4l.org/XJYlJ
//commented out declare(strict_types=1): https://3v4l.org/1bD85

class Fruit {
    // Properties
    private string $name;
    private string $color;

    // Methods
    function setName(string $name): string {
        $this->name = $name;
        return $name;
    }
    
    // Methods
    function setColor(string $color): string {
        $this->color = $color;
        return $this->color;
    }
    
    function setNameAndColor(string $name, string $color): array {
        $this->name = $name;
        $this->color = $color;
        return [$this->name, $this->color];
    }
    
    function setNameAndColorAndOptionalBoolean(string $name, string $color, bool $booleanArgument = false): array {
        $this->name = $name;
        $this->color = $color;
        return [$this->name, $this->color];
    }
    
    function getName(): string {
        return $this->name;
    }
    
    function getColor(): string {
        return $this->color;
    }
    
    function getNameAndColor(): array {
        return [$this->name, $this->color];
    }
}

$testFruit = new Fruit;

$methodsArray = [
    'setName' => '1arg',
    'setNameAndColor' => '2args',
    'setNameAndColorAndOptionalBoolean' => '3args'
];

$methodsResults = [];
foreach ($methodsArray as $methodName => $methodType) {
    if ($methodType == '1arg') {
        printf("%s - %s\n", $methodName, $methodType);
        $methodsResults[$methodName] = $testFruit->$methodName('Orange1arg', 'spurious argument');
    }
    elseif ($methodType == '2args') {
        printf("%s - %s\n", $methodName, $methodType);
        $methodsResults[$methodName] = $testFruit->$methodName('Orange2args', 'orange', true);
    }
    elseif ($methodType == '3args') {
        printf("%s - %s\n", $methodName, $methodType);
        $methodsResults[$methodName] = $testFruit->$methodName('Orange3args', true, 'orange', true);
    }
}

$getNameAndColor = $testFruit->getNameAndColor();

var_dump($testFruit, $methodsResults, $getNameAndColor);