What is float in C++
Introduction
The basic base built-in data type in C++ is called float. The numerical utilization of floating point numbers is referred to as “float.” There are several functions available in C++ language to modify and deal with floating-point values, and its floating-point data type has a memory capacity of 32 bits or 4 bytes. Only the first seven digits of a float's precision are available in C++ programming language; if this restriction is exceeded, the float shows garbage data. The numbers that may be represented by the float type in C++ range from around 1.5 * 10-45 to 3.4 *1038. Doubles have a higher range compared to floats; thus we can use them to store numbers with more accuracy values than floats can provide.
Use of float in C++:
In regards to performance, the float values are better than the double values. Because of their own internal implementation, float values process information more quickly than double values. Because they only use half of the storage bandwidth of double values, it makes sense to make use of float values on more occasions than double values since requirements are for an accuracy of seven digits or less.
Because float values outperform double values in terms of performance, they are also favored in graphical libraries, which have extremely high processing power requirements. Because float values allow programmers to set a certain number representing the decimal places with extra parameters, they are also preferred by programmers for storing records of currencies.
Float vs Double and int:
The objective of maintaining the floating point numbers is the same for both double as well as floating values. The range of values, along with memory size, are the primary distinctions between the two. In C++, the double value has a size of 64 bits, or 8 bytes, which is almost twice that of a float data type. In C++, double is the better option than float if we wish to store data with a level of accuracy of 15 to 16 decimal places.
The built-in integer data type, or int, is what's utilized to hold whole integers. Its function is entirely distinct from that of the float. In C++, an int has a size of 32 bits or 4 bytes.
Example 1:
#include <iostream>
using namespace std;
int main()
{
float float_number = 7.5986;
cout << "Float type number is : " << float_number << endl;
return 0;
}
Output:
Explanation:
The program above defines a variable called float_number of type float, to which the floating number 5.6937 is allocated. The value contained in this float_number variable was then printed. The fundamental application of float from C++ is shown by this code.
setprecision() function in float in C++:
To determine how many values with a decimal point when using floating point values will be returned with the cout, we may employ the setprecision() function that exists in C++. Here are some illustrations of floating point numbers along with precision numbers:
// precision 2
1.7
17
// precision 3
1.79
17.9
// precision 4
179.6
17.96
1.796
We must import the setprecision() function from the C++ iomanip library into our code. The acronym for input and output manipulations is iomanip.
Example of setprecision() function:
The code example that demonstrates how to define the number of values containing the decimal point within our program using the setprecision() method is shown below.
#include <iomanip>
#include <iostream>
using namespace std;
int main() {
float floatnumber = 25.78694;
cout << setprecision(5);
cout << "Floating point value precision is set to 5 : " << floatnumber << endl;
cout << setprecision(4);
cout << "Floating point value precision is set to 4 : " << floatnumber << endl;
return 0;
}
Output:
Explanation:
Having a look at the code sample above. We set the amount of values for the value to be printed with the cout by using the setprecision() function from the iomanip library. As seen in the example above, we set the value of the variable floatnumber to 25.78694. Here, when we use the setprecision() method and feed in the value 5 as an input, we receive the output 25.787, which is made up of 4 digits and is the result of rounding down the integer. As we observe in the result, the value with three digits of precision, 25.79, is what we obtain if we supply the value of 4 as an input.
Working with exponential numbers:
The exponential numbers can be represented using the float function in C++. For instance, the following can be saved to represent 51000 (i.e., 513).
float number = 51e+3
We refer to this numerical notation as scientific format, and the exponential is indicated by the symbol e+. The base of the supplied number represents the number that comes before e+, and the exponent comes after e+.
The numbers that fall outside of the accuracy range are likewise presented in this scientific manner. The numbers exceeding this are recorded with the scientific format since, as we previously learned, the accuracy range for the float values is seven digits. For instance, the stored integer 51000000 appears as 5.1e+07. In this case, the exponent value becomes seven, and the base value becomes 5.1.
Example:
#include <iostream>
using namespace std;
int main() {
float number = 41e+2;
cout << "Floating point value stored in the scientific format is : " << number << endl;
number = 41000000;
cout << "Floating point value greater than range is : " << number << endl;
return 0;
}
Output:
Explanation:
As the code sample above illustrates, two examples are provided to illustrate the scientific style. The number variable of the datatype float is first defined, and its scientific format number 41000 is assigned to it. When we display the second initialization, we can observe that the same variable, number, is allocated a value that exceeds the float type's range, indicating that it has is stored in the scientific format.
Conclusion:
One of the basic built-in datatypes in C++ is called float, and it has been employed to hold floating point numbers. As we observed above, the accuracy of a float value in C++ is around seven digits. For setting the precision of the total number of digits for a particular value while displaying with the cout, we may make use of the setprecision function available in the iomanip library in C++. In C++, the float operator may also be used to express exponential quantities. Here, the base as well as exponent values of the provided number are shown using the scientific format representation.