# log10() Function with Example in C++

C++ log10() function: Here, we are going to learn about the log10() function with example of cmath header in C++ programming language.
Submitted by IncludeHelp, on May 20, 2020

## C++ log10() function

log10() function is a library function of cmath header, it is used to get the common logarithm (the base-10 logarithm) of the given value. It accepts a value (float, double, or long double) and returns the common logarithm.

Syntax of log10() function:

C++11:

```     double log10 (double x);
float log10 (float x);
long double log10 (long double x);
double log10 (T x);
```

Parameter(s):

• x – represents the value whose common logarithm to be found.

Return value:

It returns the common logarithm of the given value x.

Note:

• If the given value is negative, it causes a domain error.
• If the given value is zero, it may cause a pole error.

Example:

```    Input:
float x = 10.0f

Function call:
log(x);

Output:
1
```

### C++ code to demonstrate the example of log10() function

```// C++ code to demonstrate the example of
// log10() function

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
float x = 0.0f;

x = 10.0f;
cout << "log10(" << x << "): " << log10(x) << endl;

x = 1.0f;
cout << "log10(" << x << "): " << log10(x) << endl;

x = 20.0f;
cout << "log10(" << x << "): " << log10(x) << endl;

x = -10.4f;
cout << "log10(" << x << "): " << log10(x) << endl;

x = 0.0f;
cout << "log10(" << x << "): " << log10(x) << endl;

x = 100.6f;
cout << "log10(" << x << "): " << log10(x) << endl;

return 0;
}
```

Output

```log10(10): 1
log10(1): 0
log10(20): 1.30103
log10(-10.4): nan
log10(0): -inf
log10(100.6): 2.0026
```

Reference: C++ log10() function