# log()

Published Oct 18, 2023
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The `log()` method in Kotlin’s `math` class is used to calculate the logarithm of a number with respect to a base value.

## Syntax

``````log(n, base)
``````
• `n`: The number of type `Double` for which the logarithm is to be calculated.
• `base`: The number of type `Double` that specifies the logarithm base.

The `.log()` method returns a value of type `Double`, the logarithm of `n` to `base`. The following values represent special cases:

• `log(n, base)` is `NaN` if either `n` or `base` are `NaN`.
• `log(n, base)` is `NaN` when `n < 0` or `base <= 0` or `base == 1.0`.
• `log(+Inf, +Inf)` is `NaN`.
• `log(+Inf, base)` is `+Inf` for `base > 1` and `-Inf` for `base < 1`.
• `log(0.0, base)` is `-Inf` for `base > 1` and `+Inf` for `base < 1`.

## Example

This example shows how to use the `log()` method to calculate the logarithm of `12` with base `2`:

```import kotlin.math.*
fun main(){    println(log(12.0,2.0))}
```

The output of this code will be:

```3.5849625007211565
```