ligo/gitlab-pages/docs/language-basics/math-numbers-tez.md
2020-01-29 16:15:03 +00:00

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---
id: math-numbers-tez
title: Math, Numbers & Tez
---
LIGO offers three built-in numerical types: `int`, `nat` and `tez`.
## Addition
Addition in ligo is acomplished by using the `+` operator. Some type constraints apply; for example you can't add `tez + nat`.
In the following example you can find a series of arithmetic operations, including various numerical types. However, some bits of the example won't compile because adding an `int` to a `nat` produces an `int`, not a `nat`. Similiar rules apply for `tez`:
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo group=a
// int + int produces int
const a: int = 5 + 10;
// nat + int produces int
const b: int = 5n + 10;
// tez + tez produces tez
const c: tez = 5mutez + 10mutez;
// you can't add tez + int or tez + nat, this won't compile
// const d: tez = 5mutez + 10n;
// two nats produce a nat
const e: nat = 5n + 10n;
// nat + int produces an int, this won't compile
// const f: nat = 5n + 10;
const g: int = 1_000_000;
```
> Pro tip: you can use underscores for readability when defining large numbers
>
>```pascaligo
>const g: int = 1_000_000;
>```
<!--CameLIGO-->
```cameligo group=a
// int + int produces int
let a: int = 5 + 10
// nat + int produces int
let b: int = 5n + 10
// tez + tez produces tez
let c: tez = 5mutez + 10mutez
// you can't add tez + int or tez + nat, this won't compile
// const d: tez = 5mutez + 10n
// two nats produce a nat
let e: nat = 5n + 10n
// nat + int produces an int, this won't compile
// const f: nat = 5n + 10
let g: int = 1_000_000
```
> Pro tip: you can use underscores for readability when defining large numbers
>
>```cameligo
>let g: int = 1_000_000;
>```
<!--ReasonLIGO-->
```reasonligo group=a
(* int + int produces int *)
let a: int = 5 + 10;
(* nat + int produces int *)
let b: int = 5n + 10;
(* tez + tez produces tez *)
let c: tez = 5mutez + 10mutez;
(* you can't add tez + int or tez + nat, this won't compile:
let d: tez = 5mutez + 10n; *)
(* two nats produce a nat *)
let e: nat = 5n + 10n;
(* nat + int produces an int, this won't compile:
let f: nat = 5n + 10; *)
let g: int = 1_000_000;
```
> Pro tip: you can use underscores for readability when defining large numbers
>
>```reasonligo
>let g: int = 1_000_000;
>```
<!--END_DOCUSAURUS_CODE_TABS-->
## Subtraction
The simpliest substraction looks like this:
> ⚠️ Even when subtracting two `nats`, the result is an `int`
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo group=b
const a: int = 5 - 10;
// substraction of two nats, yields an int
const b: int = 5n - 2n;
// won't compile, result is an int, not a nat
// const c: nat = 5n - 2n;
const d: tez = 5mutez - 1mutez;
```
<!--CameLIGO-->
```cameligo group=b
let a: int = 5 - 10
// substraction of two nats, yields an int
let b: int = 5n - 2n
// won't compile, result is an int, not a nat
// const c: nat = 5n - 2n
let d: tez = 5mutez - 1mutez
```
<!--ReasonLIGO-->
```reasonligo group=b
let a: int = 5 - 10;
(* substraction of two nats, yields an int *)
let b: int = 5n - 2n;
(* won't compile, result is an int, not a nat *)
(* let c: nat = 5n - 2n; *)
let d: tez = 5mutez - 1mutez;
```
<!--END_DOCUSAURUS_CODE_TABS-->
## Multiplication
You can multiply values of the same type, such as:
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo group=c
const a: int = 5 * 5;
const b: nat = 5n * 5n;
// you can also multiply `nat` and `tez`
const c: tez = 5n * 5mutez;
```
<!--CameLIGO-->
```cameligo group=c
let a: int = 5 * 5
let b: nat = 5n * 5n
// you can also multiply `nat` and `tez`
let c: tez = 5n * 5mutez
```
<!--ReasonLIGO-->
```reasonligo group=c
let a: int = 5 * 5;
let b: nat = 5n * 5n;
(* you can also multiply `nat` and `tez` *)
let c: tez = 5n * 5mutez;
```
<!--END_DOCUSAURUS_CODE_TABS-->
## Division
In LIGO you can divide `int`, `nat`, and `tez`. Here's how:
> ⚠️ Division of two `tez` values results into a `nat`
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo group=d
const a: int = 10 / 3;
const b: nat = 10n / 3n;
const c: nat = 10mutez / 3mutez;
```
<!--CameLIGO-->
```cameligo group=d
let a: int = 10 / 3
let b: nat = 10n / 3n
let c: nat = 10mutez / 3mutez
```
<!--ReasonLIGO-->
```reasonligo group=d
let a: int = 10 / 3;
let b: nat = 10n / 3n;
let c: nat = 10mutez / 3mutez;
```
<!--END_DOCUSAURUS_CODE_TABS-->
## From `int` to `nat` and back
You can *cast* an `int` to a `nat` and vice versa, here's how:
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo group=e
const a: int = int(1n);
const b: nat = abs(1);
```
<!--END_DOCUSAURUS_CODE_TABS-->
## Check if a value is a `nat`
You can check if a value is a `nat`, by using a syntax specific built-in function, which accepts an `int` and returns an `option(nat)`, more specifically `Some(nat)` if the provided integer is a natural number, and `None` otherwise:
<!--DOCUSAURUS_CODE_TABS-->
<!--Pascaligo-->
```pascaligo
const its_a_nat: option(nat) = is_nat(1)
```
<!--ReasonLIGO-->
```reasonligo group=e
let a: int = int(1n);
let b: nat = abs(1);
```
<!--END_DOCUSAURUS_CODE_TABS-->