[JS] Isograms

문제

An isogram is a word that has no repeating letters, consecutive or non-consecutive. Implement a function that determines whether a string that contains only letters is an isogram. Assume the empty string is an isogram. Ignore letter case.

isIsogram('Dermatoglyphics') == true 
isIsogram('aba') == false 
isIsogram('moOse') == false // -- ignore letter case

 

내가 푼 방식

2020.10.30 (15m)

function isIsogram(str) { 
  const lowerStr = str.toLowerCase() 
    for (let i = 0; i < lowerStr.length; i++) { 
      for (let j = i + 1; j < lowerStr.length; j++) { 
        if (lowerStr[i] === lowerStr[j]) { 
        	return false 
        } 
      } 
    } 
  return true 
}

 

출처: CodeWars