Numeric Types
Use int when you need to store a whole number without decimals, like 35 or 1000, and float or double when you need a floating point number (with decimals), like 9.99 or 3.14515.
int
#include <iostream>
using namespace std;
int main () {
int myNum = 5000;
cout << myNum;
return 0;
}
float
#include <iostream>
using namespace std;
int main () {
float myNum = 7.77;
cout << myNum;
return 0;
}
double
#include <iostream>
using namespace std;
int main () {
double myNum = 11.99;
cout << myNum;
return 0;
}
floatvs.doubleThe precision of a floating point value indicates how many digits the value can have after the decimal point. The precision of
floatis only six or seven decimal digits, whiledoublevariables have a precision of about 15 digits. Therefore it is safer to usedoublefor most calculations.
Scientific Numbers
A floating point number can also be a scientific number with an “e” to indicate the power of 10:
Example:
#include <iostream>
using namespace std;
int main () {
float f1 = 31e3;
double d1 = 17E4;
cout << f1 << "\n";
cout << d1;
return 0;
}
Output—->
31000
170000
