C++ Math log10
The function computes the common algorithm (base 10) of a given number.
Mathematically:
Suppose a number is 'x':
log10x = log10(x);
Syntax
float log10(float x);
double log10(double x);
long double log10(long double x);
double log10(integral x);
Note: The return_type can be float, double or long double.
Parameter
x : The value whose common logarithm is to be calculated.
Return value
Following are the return values of a given number:
| Parameter(x) | Return value |
|---|---|
x>1 |
Positive |
x=1 |
0 |
| 1>x>0 | Negative |
x=0 |
-infinity |
x<0 |
Not a Number |
Example 1
Let's see a simple example when the value of x is greater than 1.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
int x=5;
std::cout << "Value of x is : " <<x <<std::endl;
cout<<"Log value of x is : "<<log10(x);
return 0;
}
Output:
Value of x is : 5
Log value of x is : 0.69897
In this example, the value of x is 5. Therefore, the function log10 returns the positive value i.e 0.69.
Example 2
Let's see a simple example when the value of x is equal to 1.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
int x=1;
std::cout << "Value of x is : " <<x <<std::endl;
cout<<"Log value of x is : "<<log10(x);
return 0;
}
Output:
Value of x is : 1
Log value of x is : 0
In this example, the value of x is 1. Therefore, the function log10 returns the value zero.
Example 3
Let's see a simple example when the value of x is 0.3.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
float x=0.3;
std::cout << "Value of x is : " <<x <<std::endl;
cout<<"Log value of x is : "<<log10(x);
return 0;
}
Output:
Value of x is : 0.3
Log value of x is : -0.522879
In this example, the value of x is 0.3. Therefore, the function log10 returns the negative value i.e -0.52.
Example 4
Let's see a simple example when the value of x is zero.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
int x=0;
std::cout << "Value of x is : " <<x <<std::endl;
cout<<"Log value of x is : "<<log10(x);
return 0;
}
Output:
Value of x is : 0
Log value of x is : -inf
In this example, the value of x is zero. Therefore, the function log10 returns negative infinity value.
Example 5
Let's see a simple example when the value of x is -4
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
float x= -4;
std::cout << "Value of x is : " <<x <<std::endl;
cout<<"Log value of x is : "<<log10(x);
return 0;
}
Output:
Value of x is : -4
Log value of x is : nan
In this example, the value of x is -4. Therefore, the function log10 returns Not a Number(nan).