Evaluating a string as a mathematical expression in JavaScript

We are required to write a JavaScript function that takes in a stringified mathematical equation. The function should return the result of the equation provided to the function.

For example: If the equation is −

const str = '1+23+4+5-30';

Then the output should be 3

Example

The code for this will be −

const str = '1+23+4+5-30';
const compute = (str = '') => {
   let total = 0;
   str = str.match(/[+\−]*(\.\d+|\d+(\.\d+)?)/g) || [];
   while (str.length) {
      total += parseFloat(str.shift());
   };
   return total;
};
console.log(compute(str));

Output

And the output in the console will be −

3

AmitDiwan

Published on 21-Nov-2020 09:54:28

• Related Questions & Answers
• Evaluating a mathematical expression considering Operator Precedence in JavaScript
• Evaluate a boolean expression represented as string in C++
• Java Program to parse a mathematical expression and operators
• Computing zeroes (solutions) of a mathematical equation in JavaScript
• Program to evaluate s-expression as string in Python
• Write a Regular Expression to remove all special characters from a JavaScript String?
• How to pass a lambda expression as a method parameter in Java?
• How to set a String as a key for an object - JavaScript?
• Ordering string as a number in a database?
• How to add a mathematical expression in axis label in a plot created by using plot function in R?
• How to match a regular expression against a string?
• Represent Int64 as a String in C#
• Represent Int32 as a String in C#
• How to write the comparator as a lambda expression in Java?
• How can we write Callable as a lambda expression in Java?