Expression Evaluator

You can evaluate any mathematical expressions using exp4j in android studio.

Installation steps

• Download exp4j binary jar from the official site. Download

• Import exp4j into android studio by copying the jar files in app/libs folder.

• Add the following line in your module build.gradle file dependencies.

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    ...
}

Demo code

package com.example.expressionevaluator;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;

import de.congrace.exp4j.Calculable;
import de.congrace.exp4j.ExpressionBuilder;
import de.congrace.exp4j.UnknownFunctionException;
import de.congrace.exp4j.UnparsableExpressionException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Calculable calc = null;
        try {
            calc = new ExpressionBuilder("(5 * 4 * 3 * 2 * 1) / (2 * 1) * (3 * 2 * 1)").build();
            double result = calc.calculate();
            Log.d("result", result);

        } catch (UnknownFunctionException e) {
            e.printStackTrace();
        } catch (UnparsableExpressionException e) {
            e.printStackTrace();
        }
    }
}

Demo

For more

https://lallafa.objecthunter.net/exp4j/

https://github.com/codemaker2015/Expression-Evaluator