Code kata: String Calculator

Description

This function adds the elements of an expression whose format is a string. However, this expression contains some peculiarities:

• If the expression is empty or null, the function returns zero.
• If the expression has only a number, the function returns this number.
• When the expression contains several numbers, the function returns the sum of all of them. The numbers will arrive separated by commas by default.
• If any element of the expression is not a number, the function ignores it and adds all the others.
• Finally, separators can be customized. The configuration must be at the beginning of the expression. This configuration must start with a double slash, followed by the separator and another slash to mark the end of the configuration.

Example

''                // => 0
'8'               // => 8
'1,2,3,4'         // => 10
'1,2,a,3,4,5'     // => 15
'//%/1%5%3'       // => 9

Run project

Install

npm install

Run test

npm test