JavaScript Math log() method

The JavaScript math log() method returns the natural logarithm of the given number i.e. base e. If the number is negative, it returns NaN.

Syntax

The log() method is represented by the following syntax:

Parameter

num - A number.

Return

The natural logarithm of a number.

JavaScript Math log() method example

Here, we will understand log() method through various examples.

Example 1

Let's see an example to print the natural logarithm of a number.

<script>
document.writeln(Math.log(1)+"<br>");
document.writeln(Math.log(5)+"<br>");
document.writeln(Math.log(10));
</script>

Test it Now

Output:

0
1.6094379124341003
2.302585092994046

Example 2

Let's see the result of log() method in different test cases.

<script>
document.writeln(Math.log()+"<br>");
document.writeln(Math.log(-5)+"<br>");
document.writeln(Math.log(0));
</script>

Test it Now

Output:

NaN
NaN
-Infinity

Example 3

Here, you can test log() method with your own test cases.

<script>
function display()
{
  var x=document.getElementById("num").value;
  document.getElementById("result").innerHTML=Math.log(x);
}
</script>
<form>
  Enter a number: <input type="text" id="num">
  <input type="button"  onclick="display()" value="submit">
  </form>
  <p><span id="result"></span></p>

Test it Now

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