JavaScript Calculators: Simple & Compound Interest, Postfix Evaluation

Simple and Compound Interest Calculator

Develop a simple and compound interest calculator using HTML, CSS, and JavaScript.

Simple and Compound Interest Calculator (jQuery)

Develop a simple and compound interest calculator using HTML, CSS, and jQuery.

Simple-Compound-Interest-Calculator-JQ.html

    
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $('#calculate').click(function(){
    var p,t,r,si,ci,sip,cip;
    p = $("#principal").val();
    t = $("#period").val();
    r = $("#interest").val();

    si = parseInt((p*t*r)/100 );
    amount = p*Math.pow((1 +r/100),t );
    ci = amount-p;
    sip = parseInt(si)+parseInt(p);
    cip = parseFloat(ci)+parseFloat(p);

    $('#res1').html("<font size=4 face=verdana color=green>Simple Interest : "+si+"</font>");
    $('#res2').html("<font size=4 face=verdana color=green>Compound Interest : "+ci+"</font>");
    $('#res3').html("<font size=4 face=verdana color=green>Simple Interest with Principal Amount : "+sip+"</font>");
    $('#res4').html("<font size=4 face=verdana color=green>Compound Interest with Principal Amount : "+cip+"</font>");
  });
});
</script>
    
  

Postfix Expression Evaluation

Develop an application for evaluating postfix expressions using HTML, CSS, and Object-Oriented Concepts (OOCs) in JavaScript.

Postfix-Evaluation-JS.html

JavaScript Code:

    
// Stack class
class Stack {
  constructor() {
    this.items = [];
  }

  push(element) {
    this.items.push(element);
  }

  peek() {
    return this.items[this.items.length - 1];
  }

  isEmpty() {
    return this.items.length == 0;
  }

  printStack() {
    var str = "";
    for (var i = 0; i < this.items.length; i++)
      str += this.items[i] + " ";
    return str;
  }

  pop() {
    if (this.items.length == 0)
      return "Underflow";
    return this.items.pop();
  }
}

// Performs Postfix Evaluation on a given exp
function postFixEvaluation(exp) {
  var stack = new Stack();
  for (var i = 0; i < exp.length; i++) {
    var c = exp[i];
    if (!isNaN(c))
      stack.push(c - '0');
    else {
      var val1 = stack.pop();
      var val2 = stack.pop();
      if (val1 == "Underflow" || val2 == "Underflow")
        return "Can't perform postfix evaluation";
      switch (c) {
        case '+':
          stack.push(val2 + val1);
          break;
        case '-':
          stack.push(val2 - val1);
          break;
        case '/':
          stack.push(val2 / val1);
          break;
        case '*':
          stack.push(val2 * val1);
          break;
      }
    }
  }
  return stack.pop();
}

function postfixevaluate() {
  var ex, re;
  ex = document.getElementById("postfix").value;
  re = postFixEvaluation(ex);

  document.getElementById('res').innerHTML = "Evaluation of Postfix Expression <font size=6 face=verdana color=green>" + ex + "</font> is <font size=6 face=verdana color=green>" + re + "</font>";
}