The shunting yard algorithm is the right tool for this. Wikipedia is really confusing about this, but basically the algorithm works like this: Say, you want to evaluate 1 + 2 * 3 + 4. Intuitively, you “know” you have to do the 2 * 3 first, but how do you get this result? The … Read more
To extract characters from a string and to store them into a Character Array Simple Method (Using string indexing): #include<iostream> using namespace std; // Using the namespace std to use string. int main(int argc, char** argv) { string input; cout << “Enter a string: “; cin>>input; // To read the input from the user. int … Read more
See also the ScriptEngine. import java.awt.*; import java.awt.event.*; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; import javax.swing.*; class EvaluateString { public static void main(String[] args) { Runnable r = new Runnable() { @Override public void run() { JPanel gui = new JPanel(new BorderLayout(5,5)); final JTextField input = new JTextField( “Math.pow(2.6,22)+ Math.pow(3.9,15)”,19); final JTextField output = new … Read more
Try looking at the Math.NET Linq Algebra library. It can do what you are asking.