Matching brackets (simple version)

matching_brackets.js

// matching the brackets
// * one type of brackets only
// * opening must appear before closing bracket
// * pre or post padding characters should not affect the result
// * any other characters in0between anywhere should not affect the result
// 
const balanced = (arg) => {
//   
// `for char of result` should also work here  
//   
  const result = arg.split('').reduce((final, char) => {
//     
//     return-early or fail-fast pattern
//     
    if(final < 0) return final        // when we have -1, we have failed already, save time & resources, return
    
    if(char === '(') return ++final   // increment the counter when opening bracket found
    if(char === ')') return --final   // decrement, when closing bracket count
    return final                      // no change, just return the value we currently have
    
  }, 0) // start from ZERO count

  return result === 0 ? 'Balanced' : 'Nah!'
}

// test cases
// 
console.log(balanced(""))
console.log(balanced("()"))
console.log(balanced("(())"))
console.log(balanced(">> ( something() 876545678765$%^&^%$ in between( and multiple() levels too))"))
console.log(balanced("())"))