PHP函数怎样写一个判断数字奇偶的函数 PHP函数奇偶判断功能的入门编写技巧​

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<?php

function isOddOrEven(int $number): string {
  if ($number % 2 === 0) {
    return "Even"; // 偶数
  } else {
    return "Odd";   // 奇数
  }
}

// 示例
$num = 7;
echo "$num is " . isOddOrEven($num) . PHP_EOL; // 输出: 7 is Odd

$num = 12;
echo "$num is " . isOddOrEven($num) . PHP_EOL; // 输出: 12 is Even

?>

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function isOddOrEvenBitwise(int $number): string {
  if ($number & 1) {
    return "Odd";
  } else {
    return "Even";
  }
}

// 示例
$num = 15;
echo "$num is " . isOddOrEvenBitwise($num) . PHP_EOL; // 输出: 15 is Odd

$num = 20;
echo "$num is " . isOddOrEvenBitwise($num) . PHP_EOL; // 输出: 20 is Even

function isOddOrEvenFlexible($number): string {
  if (!is_numeric($number)) {
    return "Invalid input: Not a number";
  }

  $number = (int)$number; // 转换为整数

  if ($number % 2 === 0) {
    return "Even";
  } else {
    return "Odd";
  }
}

// 示例
echo isOddOrEvenFlexible(3.14) . PHP_EOL;   // 输出: Even (因为 3.14 转换为 3)
echo isOddOrEvenFlexible("10") . PHP_EOL;    // 输出: Even
echo isOddOrEvenFlexible("hello") . PHP_EOL; // 输出: Invalid input: Not a number

// 单元测试示例 (使用 PHPUnit)
use PHPUnit\Framework\TestCase;

class OddEvenTest extends TestCase {
  public function testIsOddOrEven() {
    $this->assertEquals("Even", isOddOrEven(4));
    $this->assertEquals("Odd", isOddOrEven(7));
    $this->assertEquals("Even", isOddOrEven(0));
    $this->assertEquals("Odd", isOddOrEven(-5));
    $this->assertEquals("Even", isOddOrEven(-8));
  }

  public function testIsOddOrEvenFlexible() {
    $this->assertEquals("Even", isOddOrEvenFlexible(4.2));
    $this->assertEquals("Odd", isOddOrEvenFlexible(7.9));
    $this->assertEquals("Even", isOddOrEvenFlexible("10"));
    $this->assertEquals("Invalid input: Not a number", isOddOrEvenFlexible("abc"));
  }
}