Numeric Types

Broadly speaking there are two types of integers:

• Signed (positive and negative)
• Unsigned (only positive)

Signed Integers

A signed integer is a whole number which can take the value of zero and both negative and positive values. This means that a signed integer can take values such as:

• -42
• 0
• 42

In order to achieve this one bit must be kept for tracking the sign (+ or -) of the value and thus the range of available values is smaller than an unsigned integer.

For those inclined, the range for an n-bit signed integer is -2^n-1 to 2^n-1-1.

Sway does not natively support signed integers however there is nothing stopping a library from using primitives to create types that act like signed types.

Unsigned Integers

An unsigned integer is a whole number which can take the value of zero or any positive number, but cannot be negative. This allows for one more bit of values to be used for the positive numbers and thus the positive range is significantly larger than for signed integers.

An example of available values is:

• 0
• 42

For those inclined, the range for an n-bit unsigned integer is 0 to 2ⁿ-1.

Alternative Syntax

All of the unsigned integer types are numeric types, and the byte type can also be viewed as an 8-bit unsigned integer.

Numbers can be declared with binary syntax, hexadecimal syntax, base-10 syntax, and underscores for delineation.

    let hexadecimal = 0xffffff;
    let binary = 0b10101010;
    let base_10 = 10;
    let underscore_delineated_base_10 = 100_000;
    let underscore_delineated_binary = 0x1111_0000;
    let underscore_delineated_hexadecimal = 0xfff_aaa;