Floating-point types

Learn double and floating-point numbers.

The double type

Decimal numbers in Dart are stored in the double type. A double is a 64-bit IEEE 754 floating-point number.

Example: double price = 19.99;. Decimals suit real values like money, temperature, measurements.

In Dart the division operator / always returns a double. So 5 / 2 gives 2.5, not 2. For integer division you use ~/ (we will see it later).

Scientific notation

You can write very large or very small decimals using scientific notation. For example 1e3 is 1000.0; 3.14E-2 is 0.0314.

The letter e or E means 'times 10 to the power of'. The number after it is the exponent. This form is common in physics and engineering.

The result is still a double. So var x = 1e3; makes x a double, not an int.

Exercise double variable

Declare double price = 19.99; and print it with print(price);.

Show example solution

void main() {
  double price = 19.99;
  print(price);
}

Test yourself

What is the result of 5 / 2 in Dart?
```
5 / 2
```
- 2.5
- 2
- Throws an error
- 3
Show answer

2.5 — / always returns a double.
Floating-point type
```
____ price = 9.99;
```
Show answer
```
double price = 9.99;
```
Decimal concepts

double

Floating-point
int

Integer
1e3

Scientific
/

Division (double)

Next lesson: bool and String

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