PHP 中 rad2deg 和 deg2rad 函数的区别及双向转换技巧

gitbox 2025-08-21

<?php // 正文部分 echo "

PHP 中 rad2deg 和 deg2rad 函数的区别及双向转换技巧

"; // 1. 函数简介 echo "

1. 函数简介

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在 PHP 中，处理角度与弧度的转换是常见操作，尤其在数学计算、图形绘制、物理模拟等场景中。

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rad2deg()：将弧度 (radian) 转换为角度 (degree)。

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deg2rad()：将角度 (degree) 转换为弧度 (radian)。

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"; // 2. 使用示例 echo "

2. 使用示例

"; // rad2deg 示例 $radian = pi() / 2; // 90 度对应的弧度 $degree = rad2deg($radian); echo "

将弧度 {$radian} 转换为角度：{$degree}°

"; // deg2rad 示例 $angle = 180; $radian2 = deg2rad($angle); echo "

将角度 {$angle}° 转换为弧度：{$radian2}

"; // 3. 区别分析 echo "

3. 区别分析

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两者的主要区别在于转换方向：

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rad2deg()：输入弧度，输出角度。

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deg2rad()：输入角度，输出弧度。

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数值上的计算公式分别为：

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rad2deg(radian) = radian × 180 / π

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deg2rad(degree) = degree × π / 180

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"; // 4. 双向转换技巧 echo "

4. 双向转换技巧

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在实际开发中，常需要进行双向转换。可以封装一个通用函数：

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'</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'function convertAngle($value, $type = "deg") {'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'    if ($type === "deg") {'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'        return rad2deg($value); // 弧度转角度'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'    } elseif ($type === "rad") {'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'        return deg2rad($value); // 角度转弧度'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'    } else {'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'        throw new Exception("未知类型，请使用 deg 或 rad");'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'    }'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'}'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'

'; echo "

使用示例：

"; echo '

'</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'$angleInDeg = convertAngle(pi() / 4, "deg");'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'$angleInRad = convertAngle(90, "rad");'</span></span><span> . </span><span><span>"\n"</span></span><span>;
</span><span><span>echo</span></span><span> </span><span><span>'

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这样可以根据需求灵活选择转换方向。

"; // 5. 总结 echo "

5. 总结

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rad2deg 和 deg2rad 是 PHP 中角度与弧度转换的核心函数。理解两者区别并掌握双向转换技巧，有助于在数学计算和图形处理场景中提高代码可读性和开发效率。

"; ?> <?php // 文章尾部无关内容 echo "感谢阅读本篇文章，希望你能轻松掌握 PHP 中的角度与弧度转换技巧！\n"; ?>

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