Javascript Calculator: Plus Sign Alternatives

As I was researching my current question this article seemed to be promising but I could not figure out for myself if it was the answer to my question. So if anyone could help my t

Solution 1:

Here's a very simple calculator implementation with prototypes and a module, no eval needed.

var calc = (function calcModule() {
  function Calculator(operation) {
    this.op = operation;
    this._init();
  }

  Calculator.prototype = {
    _init: function() {
      this.n1 = +this.op.split(/\D/)[0];
      this.n2 = +this.op.split(/\D/)[1];
      this.result = this[this.op.match(/\D/)[0]]();
    },
    '+': function() { return this.n1 + this.n2 },
    '-': function() { return this.n1 - this.n2 },
    '*': function() { return this.n1 * this.n2 },
    '/': function() { return this.n1 / this.n2 }
  };

  return function(op) {
    return new Calculator(op);
  };
}());

You can change what the symbols do if you want to. You use it like so:

console.log(calc('20-15').result); //=> 5
console.log(calc('15/5').result); //=> 3
...

Note that it's very simple, it'll only work with two numbers, but just so you get an idea...

Solution 2:

You could also do this:

var Atext = form.first.value.replace(/\//g,"+");
var Btext = form.second.value.replace(/\//g,"+");

Which would replace all division operators behind the scenes so that your eval will process them as addition. (So you could put 5/5/5 and get 15, or what have you.)