View source for Exp4j

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{{Notability|Products|date=June 2021}}
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{{Infobox software
| name = exp4j
| programming language = [[Java (programming language)|Java]]
| latest release version = 0.4.3
| latest release date = 2014-10-10
| license= [[Apache License 2.0]]
| genre = [[Math]]
| website = {{url|http://www.objecthunter.net/exp4j/}}
}}

'''exp4j''' is a small [[Java (programming language)|Java]] library for evaluation of mathematical expressions.<ref>{{Cite web |title=Maven Central Repository Search |url=https://search.maven.org/artifact/net.objecthunter/exp4j/0.4.8/jar |access-date=2022-03-16 |website=search.maven.org}}</ref> It implements Dijkstra's [[Shunting-yard algorithm]] to translate expressions from infix notation to [[Reverse Polish notation]] and calculates the result using a simple [[Stack (abstract data type)|Stack]] algorithm.

==Features==
* Variables can be used in expressions
* exp4j comes with a set of common built-in functions
* Users can create and use their own custom operators
* Users can create and use their own custom functions

==License terms==
'''exp4j''' is released under the terms of the [[Apache License 2.0]]

==Examples of usage==
Calculating the result of
<math>3 * \frac{\sin{(\pi)} - 2}{e}</math>
can be done in the following way:
<syntaxhighlight lang="java">
Expression e = new ExpressionBuilder("3 * (sin(pi) - 2 )/ e")
        .variables("pi", "e")
        .build()
        .setVariable("pi", Math.PI)
        .setVariable("e", Math.E);
double result = e.evaluate();
</syntaxhighlight>

==See also==
* [[Mxparser|mXparser]] - Mathematical Expressions Parser / Evaluator

==References==
{{reflist}}

[[Category:Java (programming language) libraries]]