Definition and Usage
定义与用法

The log() method returns the natural logarithm (base E) of a number.
log()方法可返回参数x 的自然对数。

Syntax
语法

Math.log(x)

Tips and Notes
提示与注意点

Note: If the parameter x is negative, NaN is returned.
注意：如果参数x是负数。返回的值为NaN

Example
举例

In the following example we will use the log() method on different numbers:
在下面的举例中我们将对不同的数字使用log()方法

<script type="text/javascript">

document.write(Math.log(2.7183) + "<br />")
document.write(Math.log(2) + "<br />")
document.write(Math.log(1) + "<br />")
document.write(Math.log(0) + "<br />")
document.write(Math.log(-1))

</script>

The output of the code above will be:
输出结果为：

1.0000066849139877
0.6931471805599453
0
-Infinity
NaN

Try-It-Yourself Demos
尝试与演示

log()
How to use log().
怎样使用log()

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