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其他参考手册

CSSStyleDeclaration JS 类型转换


JavaScript acos() 方法


实例

返回一个数的反余弦值:

Math.acos(0.5);
亲自试一试 »

定义和用法

acos() 方法返回数的反余弦,值为 0 到 PI 弧度值。

注释:如果参数 x 超出 -1 到 1 的范围,则该方法将返回 NaN。

提示:如果参数 x 取值 -1,那么将返回 PI。


浏览器支持

方法
acos() Yes Yes Yes Yes Yes

语法

Math.acos(x)

参数值

参数 描述
x 必需。必须是 -1.0 ~ 1.0 之间的数。

技术细节

返回值: 数值,从 0 到 PI,如果值超出 -1 到 1 的范围,则返回 NaN。
JavaScript 版本: ECMAScript 1