Built in Operators » Histórico » Revisión 2
Revisión 1 (Federico Vera, 2018-06-09 23:59) → Revisión 2/6 (Federico Vera, 2018-07-08 05:57)
# Built in Operators There are three basic sets of operators available: ## Arithmetic All of the arithmetic operators are included and available: `+`, `-`, `*`, `/` and of course `%` (modulo). ## Boolean Boolean operators will consider `false` every value equal to zero ([`0 ± 0.000000000001`](https://redmine.riddler.com.ar/projects/exp4j/repository/revisions/master/entry/src/main/java/net/objecthunter/exp4j/operator/Operator.java#L70)), 0.000000000001`](https://gitlab.com/riddler_arg/exp4j/blob/master/src/main/java/net/objecthunter/exp4j/operator/Operator.java#L70)), and `true` every other value. But they are warrantied to return `1.0` for `true` and `0.0` for `false`. The available operators are: `&` (and), `|` (or), `¬` (not). There are also a set of [[Extra Functions|Extra Functions and Operators]] ## Precedence For those who don't know, precedence of operators refers to which of the operators will be evaluated first when left alone. I won't bother you with numbers, the order of evaluation is as follows: ``` FIRST-> * / % - + ¬ & | == != <-LAST ----- --- - - - ----- ^^^ The dashes indicate groups with the same precedence ``` When operators have the same precedence they will be evaluated from left to right. ***Note:*** as in primary school (and beyond) you can always alter the precedence of operators with the use of parentheses. ## Factorial Factorial isn't technically an operator... it's a function but since it's so common, it's implemented by using the `!` symbol and with more precedence than the arithmetic multiplication. Even though the implementation of operators is trivial in `exp4j` the factorial is the only postfix unary operator, so it deserves a [special case](https://redmine.riddler.com.ar/projects/exp4j/repository/revisions/master/entry/src/main/java/net/objecthunter/exp4j/operator/Operator2.java#L183). case](https://gitlab.com/riddler_arg/exp4j/blob/master/src/main/java/net/objecthunter/exp4j/operator/Operators.java#L183). **Note:** Factorials from `0!` to `21!` are guaranteed to be correct, bigger than `21!` may suffer lost of precision because of `double` rounding. **Note 2:** Factorials bigger than `170!` will rise an `IllegalArgumentException` since the value will be `Double.INFINITY`. ## Code The code for the operators is [here](https://redmine.riddler.com.ar/projects/exp4j/repository/revisions/master/entry/src/main/java/net/objecthunter/exp4j/operator/Operators.java). [here](https://gitlab.com/riddler_arg/exp4j/blob/master/src/main/java/net/objecthunter/exp4j/operator/Operators.java).Volver al inicio