C Numeric Data Types
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.
float vs. double
The precision of a floating point value indicates how many digits the value can have
after the decimal point.
The precision of float is six or seven
decimal digits, while double variables have a precision
of about 15 digits. Therefore, it is often safer to use double for most calculations - but note that it takes up twice as much memory as float (8
bytes vs. 4 bytes).
Scientific Numbers
In C, you can write very large or very small floating-point numbers using scientific notation.
This is done using the letter e (or E), which stands for "times 10 to the power of".
For example, 35e3 means 35 × 10³ =
35000.
This is useful for writing numbers in a shorter way. Especially when working with scientific values or large-scale data.
Example
float f1 = 35e3; // 35 * 10^3 = 35000
double d1 = 12E4; // 12 * 10^4 = 120000
printf("%f\n", f1);
printf("%lf", d1);
Try it Yourself »
