How to write simple calculator program in JavaScript?
const number1 = parseFloat(prompt (‘Enter the first number: ‘)); const number2 = parseFloat(prompt (‘Enter the second number: ‘)); let result; // declaration of the variable. // use if, elseif and else keyword to define the calculator condition in JavaScript.
What does eval () do in JavaScript?
The eval() method evaluates or executes an argument. If the argument is an expression, eval() evaluates the expression. If the argument is one or more JavaScript statements, eval() executes the statements.
Should you use eval in JavaScript?
Never use eval()! eval() is a dangerous function, which executes the code it’s passed with the privileges of the caller. If you run eval() with a string that could be affected by a malicious party, you may end up running malicious code on the user’s machine with the permissions of your webpage / extension.
What is EVAL() METHOD in JavaScript?
JavaScript’s eval () method evaluates code represented as a string (we will use our array to temporarily store data, and afterwards we will convert it to a string), You can read more about this method in the official documentation. Action point: Create the above 3 variables.
How to perform mathematical operations in JavaScript?
The reason behind this is that to perform our mathematical operations, we are going to use the eval () method. JavaScript’s eval () method evaluates code represented as a string (we will use our array to temporarily store data, and afterwards we will convert it to a string), You can read more about this method in the official documentation.
What is evaluator JS used for?
From the README: Evaluator.js is a small, zero-dependency module for evaluating mathematical expressions. All major operations, constants, and methods are supported. Additionally, Evaluator.js intelligently reports invalid syntax, such as a misused operator, missing operand, or mismatched parentheses.
How to implement arithmetical rules without using eval()?
If you don’t want to use eval you will have to use an existing expression evaluator library. I spent a couple of hours to implement all the arithmetical rules without using eval () and finally I published a package on npm string-math.