Algorithm #02 - "1st non-repeated char?"

🇺🇸 Given an arbitrary input string, return the first nonrepeated character in the string.

🇦🇷 Dado una palabra u oracion aleatoria, retorne la primer letra no repetida en dicha palabra u oracion.

🇰🇷 임의 문자열을 인자로 받을 경우 문자열의 첫 번째 비중복 문자를 반환하십시오.

Example:

stNonRepChar('ABA');    // => 'B'
stNonRepChar('AACBDB'); // => 'C'

# START [ here ] 🏁

var stNonRepChar = function(str) {
  // Your CODE
}

// Test
stNonRepChar("AACBDB");

# Javascript solution 🏆

• Run it on your browser console window (F12) 🖥
• Please feel free to add your preference language solution 👩‍👩‍👧‍👦
• Do your best to complete the problem 🎭
• if you can't beat this the solution is below 😱

solution 👇

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SOLUTION #1

var stNonRepChar = function(str) {
  var counter = {};
  for (let i = 0; i < str.length; i++) {
    if (counter[str[i]]) {
      counter[str[i]]++;
    } else {
      counter[str[i]] = 1;
    }
  }
  for (let i = 0; i < str.length; i++) {
    if (counter[str[i]] === 1) {
      return str[i];
    }
  }
}

// Test
console.log(stNonRepChar("AACBDB"));

SOLUTION #2

var stNonRepChar = function(str) {
  for (let char of str) {
    if (str.match(new RegExp(char, "gi")).length == 1) {
      return char;
    }
  }
}

// Test
console.log(stNonRepChar("AACBDB"));

SOLUTION #3

var stNonRepChar = function(str) {
  var strTrim = str.split("");
  var result = "";
  var counter = 0;

  for (var x = 0; x < strTrim.length; x++) {
    counter = 0;

    for (var y = 0; y < strTrim.length; y++) {
      if (strTrim[x] === strTrim[y]) {
        counter += 1;
      }
    }
    if (counter < 2) {
      result = strTrim[x];
      break;
    }
  }
  return result;
}

// Test
console.log(stNonRepChar("AACBDB"));