Minimum and Maximum Values, Saturation Arithmetic, and Floating-Point Numbers

Minimum and maximum values

The minimum and maximum values for all integer and fixed-point number types are available through the fields min and max.

For example:

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let max = UInt8.max

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// `max` is 255, the maximum value of the type `UInt8`

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let max = UFix64.max

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// `max` is 184467440737.09551615, the maximum value of the type `UFix64`

Saturation arithmetic

Integers and fixed-point numbers support saturation arithmetic, which means that arithmetic operations, such as addition or multiplications, are saturating at the numeric bounds instead of overflowing.

• If the result of an operation is greater than the maximum value of the operands' type, the maximum is returned.
• If the result is lower than the minimum of the operands' type, the minimum is returned.

Saturating addition, subtraction, multiplication, and division are provided as functions with the prefix saturating:

• Int8, Int16, Int32, Int64, Int128, Int256, Fix64:

  • saturatingAdd
  • saturatingSubtract
  • saturatingMultiply
  • saturatingDivide

• Int:

  • none

• UInt8, UInt16, UInt32, UInt64, UInt128, UInt256, UFix64:

  • saturatingAdd
  • saturatingSubtract
  • saturatingMultiply

• UInt:

  • saturatingSubtract

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let a: UInt8 = 200

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let b: UInt8 = 100

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let result = a.saturatingAdd(b)

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// `result` is 255, the maximum value of the type `UInt8`

Floating-point numbers

There is no support for floating point numbers.

Smart Contracts are not intended to work with values that include error margins and therefore floating point arithmetic is not appropriate here.

Instead, consider using fixed point numbers.