Calculator In Javascript With Eval

Useful hope you enjoy coding.

Calculator in javascript with eval. It s often said that eval is evil. Our calculator will only able to perform basic math operations. This calculator uses the library big js to deal with decimal math. Just evaluate and return the result.

Long long time ago javascript was a much weaker language many things could only be done with eval. This calculator is awesome and i just want to change one thing. If the argument represents one or more javascript statements eval evaluates the statements. How come ethan ryan hasn t blogged about making a javascript calculator yet.

In this series we are going to be making a simple calculator with basic html css and javascript. I don t know javascript well but this is what i have so far. I used jasmine standalone to create unit specs for the actual math functions addition subtraction multiplication and division. Using eval in modern programming eval is used very sparingly.

There s no need to check the expression for correctness in this task. Without use strict eval doesn t have its own lexical environment so we would see x and f outside. First let s start with our html and css. If the string represents an expression eval evaluates the expression.

The argument of the eval function is a string. It can do basic math functions with decimal numbers. I know what you re thinking. Calculator without eval by diana lescure description.

The argument of this function is a string and it executes a string as javascript code. Addition subtraction multiplication and division. Thanks to css grid we can get a nice. Create a calculator that prompts for an arithmetic expression and returns its result.

Eval is a function property of the global object. I ve removed the readonly property from display so i can enter numbers and operator symbols but i want to be able to calculate by hitting enter. The reason is simple.