C++ Math logb()

The function computes the logarithm of a given number, using FLT_RADX as base for the logarithm.

Generally, FLT_RADX is equal to 2. Therefore, logb() is equivalent to log2().

Syntax

Suppose a number is ‘x’. Syntax would be:

Parameter

x: The value whose logarithm is to be calculated.

Return value

It returns base FLT_RADX logarithm of x.

If x is zero, then it may cause domain or pole error depending on the library implementation.

Example 1

Let’s see the simple example when the value of x is integer type.

Output:

Value of x is :6  logarithm value of x is:2  

In this example, the value of x is 6. The logb() function computes the logarithm of x base FLT_RADX.

Example 2

Let’s see the simple example when the value of x is float type.

Output:

Value of x is :10.4  logarithm value of x is:3  

In this example, the value of x is 10.4. The logb() function computes the logarithm of x base FLT_RADX.

Example 3

Let’s see the simple example when the value of x is zero.

Output:

Value of x is  :0  logarithm value of x is : -inf