12-calculator.md

Problem:

Create a simple calculator that given a string of operators (), +, -, *, / and numbers separated by spaces returns the value of that expression

Example:

Calculator().evaluate("2 / 2 + 3 * 4 - 6") # => 7

Calculator.new.evaluate("2 / 2 + 3 * 4 - 6") # => 7

Calculator.evaluate("2 / 2 + 3 * 4 - 6") // => 7

Calculator.evaluate "2 / 2 + 3 * 4 - 6" // => 7.0

Remember about the order of operations! Multiplications and divisions have a higher priority and should be performed left-to-right. Additions and subtractions have a lower priority and should also be performed left-to-right.

Solution